CVE-2026-53221

criticalpriority · track · 0EPSS 0.006 · 47 %ileDEEUFRRUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.58% (47th) EPSS

CVSS 9.8 · critical

Is it mine?

69 products

Check your exposure

Who says so?

7 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

In the Linux kernel, the following vulnerability has been resolved: ip6_vti: fix incorrect tunnel matching in vti6_tnl_lookup() In vti6_tnl_lookup(), when an exact match for a tunnel fails, the code falls back to searching for wildcard tunnels: - Tunnels matching the packet's local address, with any remote address wildcard remote). - Tunnels matching the packet's remote address, with any local address (wildcard local). However, vti6 stores all these different types of tunnels in the same hash table (ip6n->tnls_r_l) prone to hash collisions. The bug is that the fallback search loops in vti6_tnl_lookup() were missing checks to ensure that the candidate tunnel actually has a wildcard address.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

No vendor fix yet; a mitigation is available.

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 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 TM MFP - GNU/Linux subsystemsiemens_psirt
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.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · CISA US

v3.19.8criticalAV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · ENISA EU

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondaryexploitability 3.9 · impact 5.9

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsecondary · Siemens ProductCERT DE

v3.19criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-1289USCWE-20USCWE-20USCWE-20USCWE-20US

affected products (69)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
F5 F5OSall versionscert_bundDEcpe:/o:f5:f5os:-
F5 F5OS 1.5.1-1.5.4all versionscert_bundDEcpe:/o:f5:f5os:a_1.5.1_-_1.5.4
F5 F5OS 2.0.0all versionscert_bundDEcpe:/o:f5:f5os:2.0.0
F5 F5OS A 1.8.0-1.8.4all versionscert_bundDEcpe:/o:f5:f5os:a_1.8.0_-_1.8.4
F5 F5OS C 1.6.0-1.6.4all versionscert_bundDEcpe:/o:f5:f5os:c_1.6.0_-_1.6.4
F5 F5OS C 1.8.0-1.8.2all versionscert_bundDEcpe:/o:f5:f5os:c_1.8.0_-_1.8.2
IBM QRadar SIEMall versionscert_bundDEcpe:/a:ibm:qradar_siem:-
IBM Security Verify Accessall versionscert_bundDEcpe:/a:ibm:security_verify_access:-
Open Source Linux Kernelall versionscert_bundDEcpe:/o:linux:linux_kernel:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat Enterprise Linux 10all versionscert_bundDEcpe:/o:redhat:enterprise_linux:10
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem≤ vers:all/*cisa_csaf_otUS
Linux Linux≤ 3.19enisa_euvdEU

showing 20 of 69

advisories (6)

Vendor and ecosystem advisories describing this.

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-2026-2077Linux Kernel: Mehrere SchwachstellenDeutsch2026-06-24csaf · cert_bundDE
Ein entfernter Angreifer kann mehrere Schwachstellen im Linux Kernel ausnutzen, um Sicherheitsvorkehrungen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen und weitere, nicht näher spezifizierte Auswirkungen zu erzielen.
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-1385Multiples vulnérabilités dans les produits VMwareFrançais2026-10-26vendor · certfrFR

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund cisa_csaf_ot siemens_psirt certfr NVD CVE.org MITRE

published 2026-06-25modified 2026-10-19

references (26)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan