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VulnerabilityPublished Updated

CVE-2026-23394: Linux kernel · af_unix: Give up GC if MSG_PEEK intervened.

Affects Linux kernelSource GCVE Database

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Not known to be exploited · CVSS 4.7 Medium · fixed in 6.8.0-1057.60~22.04.1 : update Linux kernel when convenient.

Data as of 5 Nov 2026, 00:01 UTC

CVSS 3.1 base score
4.7Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.09% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 6.8.0-1057.60~22.04.1, 6.8.0-1059.65~22.04.1, 6.8.0-1058.65~22.04.1 +46
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Mar 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: 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 4 Nov 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threatsAffected
  • <6.17.0-29.29
Fixed in
  • 6.17.0-29.29
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1015.15
Fixed in
  • 6.17.0-1015.15
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1015.15
Fixed in
  • 6.17.0-1015.15
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threatsAffected
  • 6.17.0-1003.3 – 6.17.0-1017.17
10 affected builds
Fixed in–
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1018.19
Fixed in
  • 6.17.0-1018.19
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threatsAffected
  • <6.17.0-1014.14
Fixed in
  • 6.17.0-1014.14

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch fixing this issue is available in Linux kernel versions 6.8.0-1057.60~22.04.1 and later. Users should update their Linux kernel to these fixed versions or later to remediate the vulnerability. After updating, a system reboot is required to apply the changes. No additional action is required beyond applying the official kernel updates.

Description

CVE-2026-23394 is a medium-severity vulnerability in the Linux kernel's af_unix subsystem involving a race condition between garbage collection (GC) and the MSG_PEEK socket operation. The flaw causes GC to mistakenly purge the receive queue of an active socket due to incorrect file reference count handling when MSG_PEEK increments the refcount without synchronization. This can lead to improper cleanup of socket connections. The issue was introduced after a previous fix was reverted and is resolved by deferring GC when MSG_PEEK activity is detected using a memory barrier and seqcount_t signaling. Multiple Linux kernel versions prior to 6.8.0-1057.60~22.04.1 and specific older versions are affected. A fix is available in Linux kernel 6.8.0 and later updates. No known exploits in the wild have been reported.

References

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