CVE Catalog

CVE-2026-53381

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

4th percentile - higher than 4% of all known CVEs

Summary

A use-after-free (UAF) vulnerability was found in the Linux kernel's virtiofs when unmounting submounts. The issue occurs when iput() called from fuse_release_end() accesses a superblock that has already been destroyed.

Risk Assessment

An attacker could trigger a system crash (Oops) or potentially exploit the flaw for privilege escalation by initiating a submount unmount at the right moment.

Recommendation

Apply the Linux kernel patch that reverts to synchronous release requests for the auto_submounts case immediately. Update to a kernel version containing this fix.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: virtiofs: fix UAF on submount umount iput() called from fuse_release_end() can Oops if the super block has already been destroyed. Normally this is prevented by waiting for num_waiting to go down to zero before commencing with super block shutdown. This only works, however, for the last submount instance, as the wait counter is per connection, not per superblock. Revert to using synchronous release requests for the auto_submounts case, which is virtiofs only at this time.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS