CVE-2026-52942
highpriority · track · 0EPSS 0.001 · 2 %ileDEEUFRRUUSEPSS · scored 2026-10-23
In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_log: validate MAC header was set before dumping it The fallback path of dump_mac_header() guards the MAC header access only with "skb->mac_header != skb->network_header", without checking skb_mac_header_was_set(). When the MAC header is unset, mac_header is 0xffff, so the test passes and skb_mac_header(skb) returns skb->head + 0xffff, ~64 KiB past the buffer; the loop then reads dev->hard_header_len bytes out of bounds into the kernel log. This is reachable via the netdev logger: nf_log_unknown_packet() calls dump_mac_header() unconditionally, and an skb sent through AF_PACKET with PACKET_QDISC_BYPASS reaches the egress hook with mac_header still unset (__dev_queue_xmit(), which would reset it, is bypassed). Add the skb_mac_header_was_set() check the ARPHRD_ETHER path already uses, and replace the open-coded MAC header length test with skb_mac_header_len(). Only skbs with an unset MAC header are affected; valid ones are dumped as before. BUG: KASAN: slab-out-of-bounds in dump_mac_header (net/netfilter/nf_log_syslog.c:831) Read of size 1 at addr ffff88800ea49d3f by task exploit/148 Call Trace: kasan_report (mm/kasan/report.c:595) dump_mac_header (net/netfilter/nf_log_syslog.c:831) nf_log_netdev_packet (net/netfilter/nf_log_syslog.c:938 net/netfilter/nf_log_syslog.c:963) nf_log_packet (net/netfilter/nf_log.c:260) nft_log_eval (net/netfilter/nft_log.c:60) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_netdev (net/netfilter/nft_chain_filter.c:307) nf_hook_slow (net/netfilter/core.c:619) nf_hook_direct_egress (net/packet/af_packet.c:257) packet_xmit (net/packet/af_packet.c:280) packet_sendmsg (net/packet/af_packet.c:3114) __sys_sendto (net/socket.c:2265)
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
No vendor fix yet; a mitigation is available.
- 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.
- MitigationSIMATIC S7-1500 TM MFP - GNU/Linux subsystemsiemens_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 (6ES7518-4AX00-1AB0)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.
- MitigationSIMATIC S7-1500 TM MFP - GNU/Linux subsystemcisa_csaf_ot
Limit access to the interactive shell of the additional GNU/Linux subssytem to trusted personnel only.
- 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 TM MFP - GNU/Linux subsystemsiemens_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
- No fix availableSIMATIC S7-1500 TM MFP - GNU/Linux subsystemcisa_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⚠ sources disagree · medium–high · 6.5–7.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (74)
Products and version ranges known to be affected.
- Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0)≤ vers:intdot/>=3.1.7cisa_csaf_otUS
- Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0)≤ vers:intdot/>=3.1.7cisa_csaf_otUS
- Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0)≤ vers:intdot/>=3.1.7cisa_csaf_otUS
- Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0)≤ vers:intdot/>=3.1.7cisa_csaf_otUS
advisories (9)
Vendor and ecosystem advisories describing this.
- 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-457936SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.72026-10-13csaf · siemens_psirtDE
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.7 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.
- SSA-784472SSA-784472: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1.12026-10-13csaf · siemens_psirtDE
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1.1. Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.
- WID-SEC-W-2026-2056Linux Kernel: Mehrere SchwachstellenDeutsch2026-06-23csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um einen Denial-of-Service-Angriff auszulösen oder andere, nicht näher spezifizierte Angriffe durchzuführen.
- ICSA-26-295-11Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP2026-10-13icsa · cisa_csaf_otUS
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the firmware version V3.1.7 for the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP (incl. SIPLUS variant). Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.
- ICSA-26-295-16Siemens SIMATIC S7-1500 TM MFP2026-10-13icsa · cisa_csaf_otUS
Multiple vulnerabilities have been identified in the additional GNU/Linux subsystem of the SIMATIC S7-1500 TM MFP V1.1.1. Siemens is preparing fixes and recommends specific mitigations for products where fixes are not or not yet available.
- CERTFR-2026-AVI-1298Multiples vulnérabilités dans les produits SiemensFrançais2026-10-13vendor · certfrFR
- CERTFR-2026-AVI-1333Multiples vulnérabilités dans le noyau Linux d'UbuntuFrançais2026-10-16vendor · certfrFR
- CERTFR-2026-AVI-1336Multiples vulnérabilités dans les produits IBMFrançais2026-10-16vendor · certfrFR
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (27)
External citations — patches, advisories, analysis.
- https://git.kernel.org/stable/c/65ef7397eb9a296e91839f5fd10be96f23d332e7cnnvd
- https://git.kernel.org/stable/c/8a81e336da685423f5b64aac4d571e63d674c52acnnvd
- https://git.kernel.org/stable/c/a84b6fedbc97078788be78dbdd7517d143ad1a77cnnvd
- https://git.kernel.org/stable/c/af1b7699466f6556b351fa25d3dc870abfb5d310cnnvd
- https://git.kernel.org/stable/c/befb8968a2abdfa948d5600ea7f7a509a292a590cnnvd
- https://git.kernel.org/stable/c/c38d41134085193efd5b237cf513ad5b3421a60dcnnvd
- https://git.kernel.org/stable/c/d704ee9c7bc68a161684c51a7ac05b446dcf38d4cnnvd
- https://www.kernel.org/Patchcnnvd
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