CVE-2026-46168: Linux kernel · mptcp: fix scheduling with atomic in timestamp sockopt
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 May 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@7.0.0-28.28?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure@7.0.0-1009.9?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke@7.0.0-1003.4?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 issue has been fixed in linux-hwe-edge kernel versions 5.15.0-186.196 and later. Users should update to these fixed versions to mitigate the vulnerability.
Description
A vulnerability in the Linux kernel's multipath TCP (mptcp) implementation was fixed by replacing an unsafe atomic locking mechanism with a sleepable lock to prevent scheduling issues. The flaw involved using lock_sock_fast() in atomic context around functions that can sleep, which could cause kernel panics. This issue affects multiple specific Linux kernel versions prior to 5.15.0-186.196 and certain exact versions listed. A patch is available to address this problem.
References
- ubuntu.com/security/CVE-2026-46168 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46168 (opens in a new tab)
- git.kernel.org/linus/b5c52908d52c6c8eb8933264aa6087a0600fd892 (opens in a new tab)
- git.kernel.org/stable/c/7eb513b42721bee4b96da69f6188d5a7783f210d (opens in a new tab)
- git.kernel.org/stable/c/8a005fe451c73fd2b3d1faa5643c11e6bd07acfc (opens in a new tab)
- git.kernel.org/stable/c/b157dab93a7af44a84e78cf0cb311dde475cff5b (opens in a new tab)
- git.kernel.org/stable/c/b5c52908d52c6c8eb8933264aa6087a0600fd892 (opens in a new tab)
- git.kernel.org/stable/c/ebeb70e29e37cfce899309cc2665a3bfe960ed94 (opens in a new tab)
- ubuntu.com/security/notices/USN-8566-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8568-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)