CVE-2026-43388: Linux kernel · mm/damon/core: clear walk_control on inactive context in damos_walk()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
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.
CVSS:3.1/AV:L/AC:L/PR:L/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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther 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 fix is available that clears the ctx->walk_control pointer before returning an error in the damos_walk() function. Users should apply the official kernel updates that include this patch to resolve the issue. No additional mitigation is required as the vulnerability is fixed in the updated kernel versions.
Description
A use-after-free and stale pointer vulnerability in the Linux kernel's DAMON subsystem (damos_walk function) was resolved. The issue occurs when the function sets a control pointer before checking if the context is active, potentially leaving a dangling pointer if the context is inactive. This can cause a use-after-free or a permanent busy error (-EBUSY) in subsequent calls. However, the use-after-free scenario is not exploitable in practice due to the lack of callers that restart the context. The busy error only persists while the context is inactive and is cleared when the context is restarted. The vulnerability has been fixed by clearing the control pointer before returning an error.
References
- ubuntu.com/security/CVE-2026-43388 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43388 (opens in a new tab)
- git.kernel.org/linus/d210fdcac9c0d1380eab448aebc93f602c1cd4e6 (opens in a new tab)
- git.kernel.org/stable/c/9320c77134ab8d7701e20608bbf08517df4fa321 (opens in a new tab)
- git.kernel.org/stable/c/ce0aa47c963b8c3e5beace89e2b5a665a64b5b6b (opens in a new tab)
- git.kernel.org/stable/c/d210fdcac9c0d1380eab448aebc93f602c1cd4e6 (opens in a new tab)