CVE-2026-53246: Linux kernel · sctp: validate cached peer INIT chunk length in COOKIE_ECHO processing
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 3.13.0-217.268 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.13.0-217.268, 4.15.0-1206.221~14.04.1, 4.15.0-1196.209~16.04.1 +114
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 included in Linux kernel versions 3.13.0-217.268, 4.15.0-1206.221~14.04.1, 4.15.0-1196.209~16.04.1, 4.15.0-1206.221~16.04.1, 4.15.0-1189.206~16.04.1, 4.15.0-257.269~16.04.1, 4.15.0-1158.169~16.04.1, 4.15.0-257.269, 4.15.0-1196.209, and 5.4.0-1163.174~18.04.1. Users should update their Linux kernel to one of these fixed versions or later and reboot the system to apply the security patches. Due to an ABI change, recompilation and reinstallation of third-party kernel modules may be required.
Description
A vulnerability in the Linux kernel SCTP protocol implementation was resolved by adding validation for the cached peer INIT chunk length during COOKIE_ECHO processing. The flaw allowed out-of-bounds reads and potential memory corruption due to lack of bounds checking on the cached INIT chunk length. This could lead to system compromise if exploited. The issue affects specific Linux kernel versions and has been fixed in later releases. Users are advised to update and reboot to apply the fix.
References
- ubuntu.com/security/CVE-2026-53246 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53246 (opens in a new tab)
- git.kernel.org/linus/0861615c28de668669d748ef4eb913ea9262d13b (opens in a new tab)
- git.kernel.org/stable/c/0861615c28de668669d748ef4eb913ea9262d13b (opens in a new tab)
- git.kernel.org/stable/c/cc272185c9a9a4b7febc2de52eeaa3d00f19091e (opens in a new tab)
- git.kernel.org/stable/c/edccbf3d63b0a3362bc916ea72edacc1e1ca456a (opens in a new tab)
- ubuntu.com/security/notices/USN-8629-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8637-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8629-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8643-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8644-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8645-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8646-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8629-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8656-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8643-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8658-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8660-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8661-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8644-2 (opens in a new tab)