CVE-2026-43472: Linux kernel · unshare: fix unshare_fs() handling
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · patch available : update Linux kernel when convenient.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
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 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@7.0.0-1008.8?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?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 patch is available and should be applied to affected Linux kernel versions to resolve this issue. The fix ensures that a new fs_struct is allocated when CLONE_NEWNS is used in unshare(2), preventing the inconsistent state. Users should update to patched kernel versions as provided by their Linux distribution vendors.
Description
A vulnerability in the Linux kernel's unshare(2) system call handling was fixed. The issue occurs when unshare_fs() improperly manages the filesystem namespace during certain namespace cloning operations, leading to a failure that leaves the process with detached mount points for its current working directory and root. This bug has existed since the introduction of unshare(2). The vulnerability can cause unshare(2) to fail with an error and leave the process in an inconsistent state. A patch is available that ensures a new fs_struct is allocated when CLONE_NEWNS is used, preventing this condition.
References
- ubuntu.com/security/CVE-2026-43472 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43472 (opens in a new tab)
- git.kernel.org/linus/6c4b2243cb6c0755159bd567130d5e12e7b10d9f (opens in a new tab)
- git.kernel.org/stable/c/42e21e74061b0ebbd859839f81acf10efad02a27 (opens in a new tab)
- git.kernel.org/stable/c/6c4b2243cb6c0755159bd567130d5e12e7b10d9f (opens in a new tab)
- git.kernel.org/stable/c/845bf3c6963a52096d0d3866e4a92db77a0c03d8 (opens in a new tab)
- git.kernel.org/stable/c/aa9ebc084505fb26dd90f4d7a249045aad152043 (opens in a new tab)
- git.kernel.org/stable/c/af8f4be3b68ac8caa41c8e5ead0eeaf5e85e42d0 (opens in a new tab)
- git.kernel.org/stable/c/d0d99f60538ddb4a62ccaac2168d8f448965f083 (opens in a new tab)
- git.kernel.org/stable/c/d3ffc8f13034af895531a02c30b1fe3a34b46432 (opens in a new tab)
- git.kernel.org/stable/c/d7963d6997fea86a6def242ac36198b86655f912 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)