CVE-2026-43402: Linux kernel · kthread: consolidate kthread exit paths to prevent use-after-free
Source GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 4729c7b00a347fd37d0cbc265b85f2884c3e06b6 : patch Linux kernel as a priority.
Data as of 27 Oct 2026, 01:26 UTC
- Patch
- Available – fixed in 4729c7b00a347fd37d0cbc265b85f2884c3e06b6, 28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f, 5a591d7a5e48d30100943940a30a6ab41b15c672
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 8 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 Linux kernel to 4729c7b00a347fd37d0cbc265b85f2884c3e06b6, 28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f or 5a591d7a5e48d30100943940a30a6ab41b15c672.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
The described fix consolidates kthread exit paths to ensure proper cleanup and prevent use-after-free. Until a patch is confirmed and applied, avoid running untrusted code that could trigger kthread exits. Monitor official Linux kernel advisories for the availability of an official fix.
Description
CVE-2026-43402 is a critical use-after-free vulnerability in the Linux kernel's kthread exit paths. The flaw arises because kthread exit via make_task_dead() bypasses kthread_exit(), missing cleanup of the affinity_node, leading to memory corruption and potential crashes. The issue was traced to overlapping memory structures and improper cleanup causing dangling pointers. The fix consolidates all kthread exit paths to ensure proper cleanup regardless of how the thread exits.
References
- nvd.nist.gov/vuln/detail/CVE-2026-43402 (opens in a new tab)
- git.kernel.org/stable/c/28aaa9c39945b7925a1cc1d513c8f21ed38f5e4f (opens in a new tab)
- git.kernel.org/stable/c/4729c7b00a347fd37d0cbc265b85f2884c3e06b6 (opens in a new tab)
- git.kernel.org/stable/c/5a591d7a5e48d30100943940a30a6ab41b15c672 (opens in a new tab)