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VulnerabilityPublished Updated

CVE-2026-31679: Linux kernel · openvswitch: validate MPLS set/set_masked payload length

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.1 High · fixed in c1f97152df8dfb17e855ddf0fc409b7bd13e9700 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:37 UTC

CVSS 3.1 base score
7.1High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in c1f97152df8dfb17e855ddf0fc409b7bd13e9700, bd50c7484c3bb34097571c1334174fb8b7408036, 546b68ac893595877ffbd7751e5c55fd1c43ede6 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, < c1f97152df8dfb17e855ddf0fc409b7bd13e9700
Fixed in
  • c1f97152df8dfb17e855ddf0fc409b7bd13e9700
LinuxLinuxAffected
  • ≥ fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, < bd50c7484c3bb34097571c1334174fb8b7408036
Fixed in
  • bd50c7484c3bb34097571c1334174fb8b7408036
LinuxLinuxAffected
  • ≥ fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, < 546b68ac893595877ffbd7751e5c55fd1c43ede6
Fixed in
  • 546b68ac893595877ffbd7751e5c55fd1c43ede6
LinuxLinuxAffected
  • ≥ fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, < 98de18d327ef8cbbb704980e359e4872d8c28997
Fixed in
  • 98de18d327ef8cbbb704980e359e4872d8c28997
LinuxLinuxAffected
  • ≥ fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, < 68f32ef0683c8d1c05cd2e4f16818fa63ff59c6f
Fixed in
  • 68f32ef0683c8d1c05cd2e4f16818fa63ff59c6f
LinuxLinuxAffected
  • ≥ fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, < 8ed7b9930cbc3bc71f868fa79a68700ac88d586a
Fixed in
  • 8ed7b9930cbc3bc71f868fa79a68700ac88d586a

AI-suggested

A fix for this vulnerability is available and has been applied in multiple Linux kernel commits. Users should update their Linux kernel to a version that includes these fixes. Since this is not a cloud service, manual patching is required. There are no vendor advisories indicating that no action is needed or that the issue is already mitigated without patching.

Description

CVE-2026-31679 is a high-severity vulnerability in the Linux kernel's openvswitch component related to improper validation of MPLS set/set_masked action payload lengths. The vulnerability arises because the validate_set() function accepted variable-sized MPLS payloads, whereas fixed-size MPLS key data is expected. This flaw could allow malformed MPLS action payloads to be processed, potentially leading to denial of service or other impacts. The issue has been resolved by enforcing strict validation of MPLS payload lengths and rejecting invalid payloads early.

References

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