CVE-2026-43029: Linux kernel · mptcp: fix soft lockup in mptcp_recvmsg()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in 6.6.117 : patch Linux kernel soon.
Data as of 12 Nov 2026, 00:50 UTC
Thin evidence
One scorer or none| CNA (Linux) | CVSS 3.1 | 7.5 |
|---|
- Patch
- Available – fixed in 6.6.117
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 1 May 2026
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 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Linux Linux | Affected
| Fixed in– |
AI-suggested
A fix is available in Linux kernel versions 6.6.117, 6.12.59, and 6.17.8. Users should upgrade to these or later patched versions to resolve the soft lockup issue. No additional mitigation steps are indicated.
Description
A high-severity vulnerability in the Linux kernel's Multipath TCP (mptcp) implementation causes a soft lockup in the mptcp_recvmsg() function when receiving data with MSG_PEEK and MSG_WAITALL flags. This occurs because the socket buffer (skb) is not removed from the receive queue, causing the kernel to enter an infinite loop waiting for data. The issue has been fixed by modifying the code to track the last peeked skb, enabling proper waiting behavior and preventing the lockup.