CVE-2024-26826: Linux kernel · mptcp: fix data re-injection from stale subflow
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 5.15.0-1061.67~20.04.1 : patch Linux kernel soon.
Data as of 12 Nov 2026, 18:50 UTC
- Patch
- Available – fixed in 5.15.0-1061.67~20.04.1, 5.15.0-1063.72~20.04.1, 5.15.0-1059.67~20.04.1 +38
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 17 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6900-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-4 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: mptcp: fix data re-injection from stale subflow When the MPTCP PM detects that a subflow is stale, all the packet scheduler must re-inject all the mptcp-level unacked data. To avoid acquiring unneeded locks, it first try to check if any unacked data is present at all in the RTX queue, but such check is currently broken, as it uses TCP-specific helper on an MPTCP socket. Funnily enough fuzzers and static checkers are happy, as the accessed memory still belongs to the mptcp_sock struct, and even from a functional perspective the recovery completed successfully, as the short-cut test always failed. A recent unrelated TCP change - commit d5fed5addb2b ("tcp: reorganize tcp_sock fast path variables") - exposed the issue, as the tcp field reorganization makes the mptcp code always skip the re-inection. Fix the issue dropping the bogus call: we are on a slow path, the early optimization proved once again to be evil.
References
- ubuntu.com/security/CVE-2024-26826 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26826 (opens in a new tab)
- git.kernel.org/linus/b6c620dc43ccb4e802894e54b651cf81495e9598 (opens in a new tab)
- git.kernel.org/stable/c/6f95120f898b40d13fd441225ef511307853c9c2 (opens in a new tab)
- git.kernel.org/stable/c/6673d9f1c2cd984390550dbdf7d5ae07b20abbf8 (opens in a new tab)
- git.kernel.org/stable/c/b609c783c535493aa3fca22c7e40a120370b1ca5 (opens in a new tab)
- git.kernel.org/stable/c/624902eab7abcb8731b333ec73f206d38d839cd8 (opens in a new tab)
- git.kernel.org/stable/c/b6c620dc43ccb4e802894e54b651cf81495e9598 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6828-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6900-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6895-4 (opens in a new tab)