CVE-2026-97567: Linux kernel · mptcp: prevent race between disconnect() and rtx
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.8 Medium.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 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
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 that prevents the race condition by synchronously stopping the retransmission timer during disconnect. Users should apply the updated Linux kernel versions that include this fix to mitigate the issue.
Description
A race condition vulnerability in the Linux kernel's multipath TCP (mptcp) implementation was resolved. The issue involved a race between the disconnect() function and a retransmission timer (rtx), which could lead to inconsistent connection status. The fix prevents this race by using a synchronous timer stop operation.
References
- ubuntu.com/security/CVE-2026-97567 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-97567 (opens in a new tab)
- git.kernel.org/stable/c/69a7b2a912672159dda7dcf325d27752d448dfdf (opens in a new tab)
- git.kernel.org/stable/c/374da2b9be1280695ce41f108334a8f16e3e54be (opens in a new tab)
- git.kernel.org/stable/c/85c580b0d8590520ae00a15c29e9fb9c99427a3e (opens in a new tab)