CVE-2026-74586: Linux kernel · sctp: clear new_transport when removing a peer
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, 17:16 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
A patch is available and should be applied to affected Linux kernel versions. The vendor advisory confirms that this vulnerability has been fixed. Systems running vulnerable versions should update their Linux kernel to a patched release to mitigate this issue.
Description
A use-after-free vulnerability in the Linux kernel SCTP implementation was resolved by clearing a pointer to a newly added transport when removing a peer. An authenticated SCTP peer could exploit this flaw by adding and then removing a transport within the same ASCONF chunk, causing the kernel to reference freed memory when sending a HEARTBEAT. This could lead to a kernel crash or potentially other impacts. The issue was detected by a static audit and confirmed with KASAN reports. A patch is available to fix this vulnerability.
References
- nvd.nist.gov/vuln/detail/CVE-2026-74586 (opens in a new tab)
- git.kernel.org/stable/c/163847552a571bd55094291f4ffcdc1de0f14a7b (opens in a new tab)
- git.kernel.org/stable/c/291accf36febce751021888de5f15090f4875b56 (opens in a new tab)
- git.kernel.org/stable/c/31efa656cf6aface26e88f038c14f22ee6ca1500 (opens in a new tab)
- git.kernel.org/stable/c/3b539b317cd052236fed0350364ff1268996ba46 (opens in a new tab)
- git.kernel.org/stable/c/beb33f8ee1ca83acddb2a5ae80f3d22ec550b4c3 (opens in a new tab)
- git.kernel.org/stable/c/c0f973bb5118dd1b146cda3fcc8af6f6057befec (opens in a new tab)
- git.kernel.org/stable/c/ca33df36aa0143a1d04f57d2086020c12e7eddb7 (opens in a new tab)
- git.kernel.org/stable/c/db9d8e3b670f841755bc2018f178472dc6064d27 (opens in a new tab)
- ubuntu.com/security/CVE-2026-74586 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-74586 (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)