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VulnerabilityPublished Updated

CVE-2026-31673: Linux kernel · af_unix: read UNIX_DIAG_VFS data under unix_state_lock

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in e7339db13b9ddb63417b12da55fd6191e59f7442 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% 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
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in e7339db13b9ddb63417b12da55fd6191e59f7442, c3ec44ab4526bbc4b6c9fc845af86488244f4c9b, bdf206e740bf2919d818f132c8c9cc7ed91d11c0 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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
  • ≥ 5f7b0569460b7d8d01ca776430a00505a68b7584, < e7339db13b9ddb63417b12da55fd6191e59f7442
Fixed in
  • e7339db13b9ddb63417b12da55fd6191e59f7442
LinuxLinuxAffected
  • ≥ 5f7b0569460b7d8d01ca776430a00505a68b7584, < c3ec44ab4526bbc4b6c9fc845af86488244f4c9b
Fixed in
  • c3ec44ab4526bbc4b6c9fc845af86488244f4c9b
LinuxLinuxAffected
  • ≥ 5f7b0569460b7d8d01ca776430a00505a68b7584, < bdf206e740bf2919d818f132c8c9cc7ed91d11c0
Fixed in
  • bdf206e740bf2919d818f132c8c9cc7ed91d11c0
LinuxLinuxAffected
  • ≥ 5f7b0569460b7d8d01ca776430a00505a68b7584, < b9232421a77a649c9376c99fdfc8cb7f79cad34c
Fixed in
  • b9232421a77a649c9376c99fdfc8cb7f79cad34c
LinuxLinuxAffected
  • ≥ 5f7b0569460b7d8d01ca776430a00505a68b7584, < 39897df386376912d561d4946499379effa1e7ef
Fixed in
  • 39897df386376912d561d4946499379effa1e7ef
LinuxLinuxAffected
  • ≥ 5f7b0569460b7d8d01ca776430a00505a68b7584, < 900a4e0910e98b8caef117d5df00471fa438dcf9
Fixed in
  • 900a4e0910e98b8caef117d5df00471fa438dcf9

AI-suggested

A fix is available and has been applied in multiple Linux kernel commits as listed in the establishedFacts.fixedVersions. Users and administrators should update to a Linux kernel version that includes these fixes to mitigate this vulnerability.

Description

CVE-2026-31673 is a high-severity vulnerability in the Linux kernel affecting version 3.3. It involves improper handling of UNIX_DIAG_VFS data under the unix_state_lock, where inode and device numbers were read without holding the lock, potentially causing data instability. The issue has been resolved by ensuring the VFS data is read while holding the unix_state_lock and emitting the netlink attribute after releasing the lock to maintain data stability during reply construction.

References

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