Incorrect authorization in Linux kernel - CVE-2026-98215

Vulnerability details

The vulnerability allows a local user to cause a denial of service through incorrect access denials.

The vulnerability exists due to incorrect propagation of the user security identifier in the SELinux backing-file security allocation logic when mapping files with nested backing files. A local user can invoke mprotect(PROT_READ) on such a file mapping to cause a denial of service through incorrect access denials.

The access denial was demonstrated with SELinux enforcing and two nested overlayfs mounts. Nested backing files can also occur with FUSE passthrough backed by overlayfs.

Affected software

How to mitigate CVE-2026-98215

External References

• https://git.kernel.org/stable/c/6aaeec59aadcd1eafc18b049f1b759fb6b9d9569
• https://git.kernel.org/stable/c/8c0c602202b9a4909b00bc3354e3c0355bc69e65
• https://git.kernel.org/stable/c/9d99b770e7b67b00bdef9005b928aad13e1d679b
• https://git.kernel.org/stable/c/caa1b913d90d5dc07073733326d2af0f0288f089
• https://git.kernel.org/stable/c/ff20d16b2e8230c034e21540043df47222dcc09b

Related Security Bulletins

• Incorrect authorization in Linux kernel selinux include
• Debian update for linux