CVE-2026-46170: Linux kernel · mptcp: pm: ADD_ADDR rtx: free sk if last
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 6.8.0-1064.67~22.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 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 – fixed in 6.8.0-1064.67~22.04.1, 6.8.0-1067.75~22.04.1, 6.8.0-1065.72~22.04.1 +41
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
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 included in updated Ubuntu Linux kernel packages. Users should apply the kernel updates to versions 7.0.0-28.28 or later (and corresponding patched builds) and reboot their systems to complete remediation. Due to an ABI change, third-party kernel modules must be recompiled and reinstalled after the update. No additional mitigation steps are required beyond applying the official fix.
Description
A medium severity vulnerability (CVE-2026-46170) in the Linux kernel's Multipath TCP (MPTCP) implementation was resolved. The issue involves improper handling of socket references during retransmission of ADD_ADDR messages, which could cause indefinite waiting in the timer handler and potentially lead to denial of service. Multiple Linux kernel versions prior to 7.0.0-28.28 and related builds are affected. A patch is available and included in updated Ubuntu kernel packages. Users should update and reboot to apply the fix.
References
- ubuntu.com/security/CVE-2026-46170 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-46170 (opens in a new tab)
- git.kernel.org/linus/b7b9a461569734d33d3259d58d2507adfac107ed (opens in a new tab)
- git.kernel.org/stable/c/8143a224785ceaf2b0856e08d4498916f38228fb (opens in a new tab)
- git.kernel.org/stable/c/b74ad20198652b6b39a761c277ba65ae82b1e107 (opens in a new tab)
- git.kernel.org/stable/c/b7b9a461569734d33d3259d58d2507adfac107ed (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-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8729-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8761-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)