CVE-2025-21830: Linux kernel · landlock: Handle weird files
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.3 High · fixed in 5.15.0-1084.91~20.04.1 : patch Linux kernel soon.
Data as of 12 Nov 2026, 19:33 UTC
- Patch
- Available – fixed in 5.15.0-1084.91~20.04.1, 5.15.0-1089.98~20.04.1, 5.15.0-1083.92~20.04.1 +62
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Mar 2025
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-7510-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7512-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-6 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther 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 by updating the Linux kernel to one of the fixed versions starting from 5.15.0-1084.91~20.04.1 or later. After applying the update, a system reboot is required to complete remediation. Users should follow the vendor advisory instructions for updating their systems accordingly.
Description
CVE-2025-21830 is a vulnerability in the Linux kernel's landlock security module where corrupted filesystems like bcachefs might return unusual files. Instead of warning and denying access, the kernel treated these files as regular, potentially leading to improper handling. This flaw has been fixed in several Linux kernel versions starting from 5.15.0-1084.91~20.04.1 and later. The vulnerability has a high severity with a CVSS score of 7.3 and impacts system integrity and availability.
References
- ubuntu.com/security/CVE-2025-21830 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2025-21830 (opens in a new tab)
- git.kernel.org/linus/49440290a0935f428a1e43a5ac8dc275a647ff80 (opens in a new tab)
- git.kernel.org/stable/c/0fde195a373ab1267e60baa9e1a703a97e7464cd (opens in a new tab)
- git.kernel.org/stable/c/2569e65d2eb6ac1afe6cb6dfae476afee8b6771a (opens in a new tab)
- git.kernel.org/stable/c/39bb3d56f1c351e76bb18895d0e73796e653d5c1 (opens in a new tab)
- git.kernel.org/stable/c/49440290a0935f428a1e43a5ac8dc275a647ff80 (opens in a new tab)
- git.kernel.org/stable/c/7d6121228959ddf44a4b9b6a177384ac7854e2f9 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7512-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-7511-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7521-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7510-6 (opens in a new tab)