CVE-2026-74587: Linux kernel · sctp: fix use-after-free of cached ASCONF chunk
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.15.0-1117.124~20.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 15:59 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 42% 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 +27
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 22 Aug 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
An official patch is available and should be applied promptly. The vendor advisory from Ubuntu confirms that the issue is fixed in updated Linux kernel packages. Users should update to the fixed kernel versions and reboot systems to apply the changes. No additional mitigation steps are indicated by the vendor advisory.
Description
A use-after-free vulnerability in the Linux kernel SCTP implementation was resolved. The issue involves improper handling of a cached ASCONF chunk pointer during peer restart and timer expiry, leading to potential double free and null pointer dereference. This flaw could allow an attacker to cause system compromise. Multiple specific Linux kernel versions are affected. A patch is available to fix the issue.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74587 (opens in a new tab)
- git.kernel.org/stable/c/07daf4f9750104960a1d60831b2353c0d41f35fb (opens in a new tab)
- git.kernel.org/stable/c/10459b03e2d9ee12435e96f587de4d4cacdbf435 (opens in a new tab)
- git.kernel.org/stable/c/179676f0166230c80053a392303485b37c93dd33 (opens in a new tab)
- git.kernel.org/stable/c/618b5c6d049896fcfabb91afc072954c92cb2693 (opens in a new tab)
- git.kernel.org/stable/c/8c283e7b56adce00193837f3311b06662466fb21 (opens in a new tab)
- git.kernel.org/stable/c/d949992bc3f00027a2c755e860a11950c75f6073 (opens in a new tab)
- git.kernel.org/stable/c/dc67d528c2fa939cec7fe3bf7f3089c8d281ca3d (opens in a new tab)
- git.kernel.org/stable/c/e1bb114e09372fd6e03387ced9ef566da336ed6c (opens in a new tab)
- ubuntu.com/security/CVE-2026-74587 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74587 (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-74587.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)