CVE-2026-43284
highpriority · track · 43EPSS 0.942 · 100 %ileexploit · functionalCHDEEUNLRUUSEPSS · scored 2026-10-22
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: avoid in-place decrypt on shared skb frags MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(), so later paths that may modify packet data can first make a private copy. The IPv4/IPv6 datagram append paths did not set this flag when splicing pages into UDP skbs. That leaves an ESP-in-UDP packet made from shared pipe pages looking like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW fast path for uncloned skbs without a frag_list and decrypts in place over data that is not owned privately by the skb. Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching TCP. Also make ESP input fall back to skb_cow_data() when the flag is present, so ESP does not decrypt externally backed frags in place. Private nonlinear skb frags still use the existing fast path. This intentionally does not change ESP output. In esp_output_head(), the path that appends the ESP trailer to existing skb tailroom without calling skb_cow_data() is not reachable for nonlinear skbs: skb_tailroom() returns zero when skb->data_len is nonzero, while ESP tailen is positive. Thus ESP output will either use the separate destination-frag path or fall back to skb_cow_data().
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedIndustrialPI OS 10.06.2025 installed on IndustrialPI 4pilz_psirt
Update to Firmware IndustrialPI OS 17.06.2026 or later.
- FixedIndustrialPI OS 23.06.2025 installed on IndustrialPI 4pilz_psirt
Update to Firmware IndustrialPI OS 17.06.2026 or later.
- FixedIndustrialPI OS 25.12.2025 installed on IndustrialPI 4pilz_psirt
Update to Firmware IndustrialPI OS 17.06.2026 or later.
- Fixedlinux-image-revpi-v8 < 6.12.91-revpi0-rpi-v8 default component of IndustrialPI OS 10.06.2025 installed on IndustrialPI 4pilz_psirt
Update kernel package linux-image-revpi-v8 to version 6.12.91-revpi0-rpi-v8 or higher.
- Fixedlinux-image-revpi-v8 < 6.12.91-revpi0-rpi-v8 default component of IndustrialPI OS 23.06.2025 installed on IndustrialPI 4pilz_psirt
Update kernel package linux-image-revpi-v8 to version 6.12.91-revpi0-rpi-v8 or higher.
- Fixedlinux-image-revpi-v8 < 6.12.91-revpi0-rpi-v8 default component of IndustrialPI OS 25.12.2025 installed on IndustrialPI 4pilz_psirt
Update kernel package linux-image-revpi-v8 to version 6.12.91-revpi0-rpi-v8 or higher.
- FixedAPROLabb_psirt
For affected products, software updates should be installed upon availability. Product Patch version - APROL : APROL-AutoYaST-DVD- V4.4-010.10.260602 Until remediated software versions are available, customers are required to conduct a risk assessment of their affected systems and to implement the mitigation measures and workarounds specified in this advisory.
- FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)siemens_psirt
Update to V3.1.7 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/ - FixedSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)siemens_psirt
Update to V3.1.7 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/ - FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)siemens_psirt
Update to V3.1.7 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/ - FixedSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)siemens_psirt
Update to V3.1.7 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/ - FixedSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)siemens_psirt
Update to V3.1.7 or later version
https://support.industry.siemens.com/cs/ww/en/view/109478459/ - FixedAPROLcisa_csaf_ot
For affected products, software updates should be installed upon availability. Product Patch version - APROL : APROL-AutoYaST-DVD- V4.4-010.10.260602 Until remediated software versions are available, customers are required to conduct a risk assessment of their affected systems and to implement the mitigation measures and workarounds specified in this advisory.
- MitigationLinux for B&Rabb_psirt
Successful exploitation of the vulnerabilities described in this advisory requires local access to the affected system with low-privileged user credentials. Customers are strongly advised to enforce strict access control policies on all Linux-based systems, ensuring that interactive access is exclusively granted to authorized and trusted personnel. This includes reviewing and hardening user account permissions and disabling unused accounts. Refer to section “General security recommendations” for further advise on how to keep your system secure.
- MitigationX20EDS410abb_psirt
Successful exploitation of the vulnerabilities described in this advisory requires local access to the affected system with low-privileged user credentials. Customers are strongly advised to enforce strict access control policies on all Linux-based systems, ensuring that interactive access is exclusively granted to authorized and trusted personnel. This includes reviewing and hardening user account permissions and disabling unused accounts. Refer to section “General security recommendations” for further advise on how to keep your system secure.
- MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)siemens_psirt
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)siemens_psirt
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)siemens_psirt
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)siemens_psirt
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)siemens_psirt
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationLinux for B&Rcisa_csaf_ot
Successful exploitation of the vulnerabilities described in this advisory requires local access to the affected system with low-privileged user credentials. Customers are strongly advised to enforce strict access control policies on all Linux-based systems, ensuring that interactive access is exclusively granted to authorized and trusted personnel. This includes reviewing and hardening user account permissions and disabling unused accounts. Refer to section “General security recommendations” for further advise on how to keep your system secure.
- MitigationX20EDS410cisa_csaf_ot
Successful exploitation of the vulnerabilities described in this advisory requires local access to the affected system with low-privileged user credentials. Customers are strongly advised to enforce strict access control policies on all Linux-based systems, ensuring that interactive access is exclusively granted to authorized and trusted personnel. This includes reviewing and hardening user account permissions and disabling unused accounts. Refer to section “General security recommendations” for further advise on how to keep your system secure.
- MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)cisa_csaf_ot
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)cisa_csaf_ot
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)cisa_csaf_ot
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)cisa_csaf_ot
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)cisa_csaf_ot
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- MitigationAPM Edgecisa_csaf_ot
Disable the esp4 and esp6 modules [2]
- WorkaroundLinux for B&Rabb_psirt
Security researchers have identified and validated the following workarounds to reduce exposure to the vulnerabilities described in this advisory. These measures do not remediate the underlying vulnerabilities but effectively block known attack vectors until patched software versions are deployed. Important: Customers are advised to thoroughly test their systems after applying any of the listed workarounds. B&R has no visibility into customer-specific applications running on the underlying Linux system. It is the customer's responsibility to assess whether the applied workarounds interfere with existing application workloads prior to deployment in production environments. For Debian-based systems within an active support lifecycle, kernel patches addressing CVE-2026-31431 are already available via the official package repositories. Customers are strongly encouraged to apply these updates immediately by executing the following command: sudo apt update && sudo apt upgrade A system reboot is required after the upgrade for the updated kernel to take effect. Temporary Mitigation: If an immediate system update is not feasible, the affected kernel module (algif_aead) can be disabled persistently. Security researchers have confirmed this measure effectively prevents exploitation of CVE-2026-31431. Execute the following commands as root: echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface from the kernel cryp-to API. This does not affect dm-crypt/LUKS, kTLS, IPsec/XFRM, OpenSSL, GnuTLS, NSS, or SSH. Applications explicitly configured to use the afalg engine or that directly bind aead, skcipher, or hash sockets via AF_ALG may be affected. To assess exposure prior to applying this workaround, run: lsof | grep AF_ALG
- WorkaroundX20EDS410abb_psirt
Security researchers have identified and validated the following workarounds to reduce exposure to the vulnerabilities described in this advisory. These measures do not remediate the underlying vulnerabilities but effectively block known attack vectors until patched software versions are deployed. Important: Customers are advised to thoroughly test their systems after applying any of the listed workarounds. B&R has no visibility into customer-specific applications running on the underlying Linux system. It is the customer's responsibility to assess whether the applied workarounds interfere with existing application workloads prior to deployment in production environments. For Debian-based systems within an active support lifecycle, kernel patches addressing CVE-2026-31431 are already available via the official package repositories. Customers are strongly encouraged to apply these updates immediately by executing the following command: sudo apt update && sudo apt upgrade A system reboot is required after the upgrade for the updated kernel to take effect. Temporary Mitigation: If an immediate system update is not feasible, the affected kernel module (algif_aead) can be disabled persistently. Security researchers have confirmed this measure effectively prevents exploitation of CVE-2026-31431. Execute the following commands as root: echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface from the kernel cryp-to API. This does not affect dm-crypt/LUKS, kTLS, IPsec/XFRM, OpenSSL, GnuTLS, NSS, or SSH. Applications explicitly configured to use the afalg engine or that directly bind aead, skcipher, or hash sockets via AF_ALG may be affected. To assess exposure prior to applying this workaround, run: lsof | grep AF_ALG
- WorkaroundLinux for B&Rcisa_csaf_ot
Security researchers have identified and validated the following workarounds to reduce exposure to the vulnerabilities described in this advisory. These measures do not remediate the underlying vulnerabilities but effectively block known attack vectors until patched software versions are deployed. Important: Customers are advised to thoroughly test their systems after applying any of the listed workarounds. B&R has no visibility into customer-specific applications running on the underlying Linux system. It is the customer's responsibility to assess whether the applied workarounds interfere with existing application workloads prior to deployment in production environments. For Debian-based systems within an active support lifecycle, kernel patches addressing CVE-2026-31431 are already available via the official package repositories. Customers are strongly encouraged to apply these updates immediately by executing the following command: sudo apt update && sudo apt upgrade A system reboot is required after the upgrade for the updated kernel to take effect. Temporary Mitigation: If an immediate system update is not feasible, the affected kernel module (algif_aead) can be disabled persistently. Security researchers have confirmed this measure effectively prevents exploitation of CVE-2026-31431. Execute the following commands as root: echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface from the kernel cryp-to API. This does not affect dm-crypt/LUKS, kTLS, IPsec/XFRM, OpenSSL, GnuTLS, NSS, or SSH. Applications explicitly configured to use the afalg engine or that directly bind aead, skcipher, or hash sockets via AF_ALG may be affected. To assess exposure prior to applying this workaround, run: lsof | grep AF_ALG
- WorkaroundX20EDS410cisa_csaf_ot
Security researchers have identified and validated the following workarounds to reduce exposure to the vulnerabilities described in this advisory. These measures do not remediate the underlying vulnerabilities but effectively block known attack vectors until patched software versions are deployed. Important: Customers are advised to thoroughly test their systems after applying any of the listed workarounds. B&R has no visibility into customer-specific applications running on the underlying Linux system. It is the customer's responsibility to assess whether the applied workarounds interfere with existing application workloads prior to deployment in production environments. For Debian-based systems within an active support lifecycle, kernel patches addressing CVE-2026-31431 are already available via the official package repositories. Customers are strongly encouraged to apply these updates immediately by executing the following command: sudo apt update && sudo apt upgrade A system reboot is required after the upgrade for the updated kernel to take effect. Temporary Mitigation: If an immediate system update is not feasible, the affected kernel module (algif_aead) can be disabled persistently. Security researchers have confirmed this measure effectively prevents exploitation of CVE-2026-31431. Execute the following commands as root: echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf rmmod algif_aead 2>/dev/null || true Impact assessment: Disabling the algif_aead module removes the AEAD socket interface from the kernel cryp-to API. This does not affect dm-crypt/LUKS, kTLS, IPsec/XFRM, OpenSSL, GnuTLS, NSS, or SSH. Applications explicitly configured to use the afalg engine or that directly bind aead, skcipher, or hash sockets via AF_ALG may be affected. To assess exposure prior to applying this workaround, run: lsof | grep AF_ALG
- No fix availableSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)siemens_psirt
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)siemens_psirt
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)siemens_psirt
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)siemens_psirt
Currently no fix is available
- No fix availableSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)siemens_psirt
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)cisa_csaf_ot
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)cisa_csaf_ot
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)cisa_csaf_ot
Currently no fix is available
- No fix availableSIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)cisa_csaf_ot
Currently no fix is available
- No fix availableSIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0)cisa_csaf_ot
Currently no fix is available
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (46)
Public proof-of-concept and weaponised exploit code.
- exploit/linux/local/cve_2026_43284_dirty_fragxfrm-ESP Page-Cache Write via CVE-2026-43284functional · metasploit
- EDB-52585Linux Kernel - Local Privilege EscalationPoC · exploit_db
- EDB-52591Linux Kernel - Local Privilege EscalationPoC · exploit_db
- 0xBlackash/CVE-2026-43284CVE-2026-43284PoC · poc_in_github
affected products (96)
Products and version ranges known to be affected.
advisories (11)
Vendor and ecosystem advisories describing this.
- NCSC-2026-0431Kwetsbaarheden verholpen in IBM DataPower Gateway en onderliggende componentenNL2026-10-16csaf · ncsc_nlNL
IBM heeft meerdere beveiligingsproblemen opgelost in DataPower Gateway versies 10.5 tot 11.0 en een veelvoud aan onderliggende subcomponenten.
- PPSA-2026-003Pilz: Multiple Vulnerabilities affecting industrial PC IndustrialPI2026-08-04csaf · pilz_psirtDE
The Linux kernel used in the IndustrialPI, 'linux-image-revpi-v8', prior to version 6.12.91-revpi0-rpi-v8 contains multiple vulnerabilities. Successful exploitation of these vulnerabilities can give an attacker full control over the device.
- SA26P010Impact of Linux Kernel vulnerabilities on B&R products2026-06-11csaf · abb_psirtCH
B&R is aware of publicly reported vulnerabilities affecting the Linux kernel versions shipped with the products listed as affected in the advisory. Successful local exploitation of these vulnerabilities could allow an attacker to escalate privileges on the affected system. Public proof-of-concept exploits are available for the vulnerabilities described herein. At the time of publication of this advisory, B&R had no evidence of active exploitation targeting B&R products.
- SSA-019113SSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.62026-07-14csaf · siemens_psirtDE
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.6 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens is preparing further fix versions and recommends specific countermeasures for products where fixes are not, or not yet available. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6 is no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1.6 only; for version V3.1.7 refer to SSA-457936.
- SSA-082556SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.52025-06-10csaf · siemens_psirtDE
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.5 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens is preparing further fixes and recommends specific mitigations for products where fixes are not or not yet available. SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5 is no longer maintained and there won't be any update to the CVE list anymore. Please update to the latest version. Note: This SSA advises vulnerabilities for firmware version V3.1.5 only; for version V3.1.6 refer to SSA-019113.
- WID-SEC-W-2026-1430Linux Kernel (Dirty Frag): Mehrere Schwachstellen ermöglichen Erlangen von AdministratorrechtenDeutsch2026-05-07csaf · cert_bundDE
Ein lokaler Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um Administratorrechte zu erlangen.
- WID-SEC-W-2026-2437Oracle Communications: Mehrere SchwachstellenDeutsch2026-07-21csaf · cert_bundDE
Ein entfernter, anonymer oder authentisierter Angreifer kann mehrere Schwachstellen in Oracle Communications ausnutzen, um die Vertraulichkeit, Integrität und Verfügbarkeit zu gefährden.
- WID-SEC-W-2026-3623IBM DataPower Gateway: Mehrere SchwachstellenDeutsch2026-09-28csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in IBM DataPower Gateway ausnutzen, um beliebigen Programmcode auszuführen, erweiterte Berechtigungen zu erlangen, Sicherheitsmaßnahmen zu umgehen, Daten zu manipulieren oder offenzulegen, einen Denial-of-Service-Zustand auszulösen oder Cross-Site-Scripting-Angriffe durchzuführen.
- ICSA-26-174-06Impact of Linux Kernel vulnerabilities on B&R products2026-06-11icsa · cisa_csaf_otUS
B&R is aware of publicly reported vulnerabilities affecting the Linux kernel versions shipped with the products listed as affected in the advisory. Successful local exploitation of these vulnerabilities could allow an attacker to escalate privileges on the affected system. Public proof-of-concept exploits are available for the vulnerabilities described herein. At the time of publication of this advisory, B&R had no evidence of active exploitation targeting B&R products.
- ICSA-26-209-04Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP2026-07-14icsa · cisa_csaf_otUS
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.6 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens is preparing fix versions and recommends specific countermeasures for products where fixes are not, or not yet available.
- ICSA-26-225-04Hitachi Energy APM Edge Product2026-07-28icsa · cisa_csaf_otUS
Hitachi Energy is aware of Dirty Frag vulnerabilities that affect APM Edge product versions listed in this document. Successful exploitation of these vulnerabilities could result in impact on confidentiality, integrity and availability of the product. Please refer to the Recommended Immediate Actions for information about the mitigation/remediation.
also known as (7)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (73)
External citations — patches, advisories, analysis.
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-43284cnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2026-43284cnnvd
- https://www.kernel.org/Patchcnnvd
- https://git.kernel.org/stable/c/50ed1e7873100f77abad20fd31c51029bc49cd03enisa_euvd
- https://git.kernel.org/stable/c/52646cbd00e765a6db9c3afe9535f26218276034enisa_euvd
- https://git.kernel.org/stable/c/5d55c7336f8032d434adcc5fab987ccc93a44aecenisa_euvd
- https://git.kernel.org/stable/c/71a1d9d985d26716f74d21f18ee8cac821b06e97enisa_euvd
- https://git.kernel.org/stable/c/8253aab4659ca16116b522203c2a6b18dccacea7enisa_euvd
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