Use-after-free in Linux kernel - CVE-2026-99171

Vulnerability details

The vulnerability allows a local user to potentially cause a denial of service through a kernel use-after-free.

The vulnerability exists due to use-after-free in the Linux kernel ntfs3 filesystem when an RCU path lookup accesses superblock private information after the last mount reference is dropped. A local user can potentially trigger a lookup on a filesystem mounted with the "nocase" option concurrently with mount teardown to access prematurely freed memory and cause a kernel crash.

Affected software

How to mitigate CVE-2026-99171

External References

• https://git.kernel.org/stable/c/7abecef26a9be8f9de70659a3092250461a52072
• https://git.kernel.org/stable/c/c01b091b06412d3b1b53d8c2925f6de586c8a2fc
• https://git.kernel.org/stable/c/c8b1a4840467930e01f1a9374d991d7a8a2896c1

Related Security Bulletins

• Use-after-free in Linux kernel ntfs3
• Debian update for linux