CVE-2026-23394: Linux kernel · af_unix: Give up GC if MSG_PEEK intervened.
Affects Linux kernelSource GCVE Database
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
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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.
Patches and advisories
- ubuntu.com/security/notices/USN-8277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8277-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8374-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8440-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in
|
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther threats | Affected
| Fixed in
|
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
- ubuntu.com/security/CVE-2026-23394 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23394 (opens in a new tab)
- git.kernel.org/linus/e5b31d988a41549037b8d8721a3c3cae893d8670 (opens in a new tab)
- git.kernel.org/stable/c/37dd7ab332396eb8dd80b2dc7ea4b61abf767436 (opens in a new tab)
- git.kernel.org/stable/c/e5b31d988a41549037b8d8721a3c3cae893d8670 (opens in a new tab)
- ubuntu.com/security/notices/USN-8277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8277-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8296-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8278-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8374-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8440-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8499-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8508-1 (opens in a new tab)