CVE-2026-53223: Linux kernel · net: guard timestamp cmsgs to real error queue skbs
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.1 High · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +69
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 25 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 fix is available and has been applied in linux-azure kernel versions 5.15.0-1117.124~20.04.1 and later. Users should upgrade to these fixed versions or newer to remediate this vulnerability. No additional vendor mitigation guidance indicates the need for other actions.
Description
A vulnerability in the Linux kernel's networking subsystem related to handling timestamp control messages on AF_PACKET sockets has been resolved. The flaw involves incorrect assumptions in skb_is_err_queue() about packet ownership and markings, which can lead to out-of-bounds memory reads and potential information disclosure. This issue affects specific linux-azure kernel versions and has been fixed in later releases.
References
- ubuntu.com/security/CVE-2026-53223 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53223 (opens in a new tab)
- git.kernel.org/linus/1ee90b77b727df903033db873c75caac5c27ec98 (opens in a new tab)
- git.kernel.org/stable/c/1ee90b77b727df903033db873c75caac5c27ec98 (opens in a new tab)
- git.kernel.org/stable/c/24a0d548d3a765cd4558224e4f8e06e14cba26e3 (opens in a new tab)
- git.kernel.org/stable/c/3dde4fb941fa5649ab809f6cd3e20e0c424a4e31 (opens in a new tab)
- git.kernel.org/stable/c/71ff5cdd5da61d0438e902aa0fd68c28bc901abe (opens in a new tab)
- git.kernel.org/stable/c/ad9a0374ee6d11048e1f74cd5180bad58b9848b4 (opens in a new tab)
- git.kernel.org/stable/c/b903e9b5629ec8dd6db92174070045bf81ad7060 (opens in a new tab)
- git.kernel.org/stable/c/e0665b2a8e90bb08bd205062c75662b502d31797 (opens in a new tab)
- git.kernel.org/stable/c/eb51a9ad3ceb01bc6c0fb608dbc856e03ee6f24a (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-53223 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)