CVE-2026-53394

High

In the Linux kernel, the following vulnerability has been resolved: nfsd: avoid leaking pre-allocated openowner on unconfirmed retry race When find_or_alloc_open_stateowner() encounters an unconfirmed owner, it calls release_openowner() and sets oo = NULL. Control then falls through past the `if (oo)` guard -- which would have freed any pre-allocated `new` -- and unconditionally executes `new = alloc_stateowner(...)`. If `new` was already allocated on a prior iteration, the pointer is silently overwritten and the previous allocation (slab object + owner name buffer) is leaked. This requires a race: two NFSv4.0 OPEN threads with the same owner string, where a concurrent thread inserts a new unconfirmed owner into the hash between retry iterations. The window is narrow but repeatable under adversarial conditions. Fix by adding `goto retry` after `oo = NULL` so the already-allocated `new` is reused on the next iteration rather than overwritten.

Package Linux Kernel
Published 2026-07-19
Last modified 2026-08-17
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.5

out of 10
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
High
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness type

CWE-401

CVE-2026-53394 is a Memory Leak vulnerability

What is Memory Leak?

The product does not release memory after use, causing gradual resource exhaustion. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.10 and later are affected. Fixed in 6.12.95, 6.18.38, 7.1.3, 7.2 and their respective stable series.

Affected from
≥ 6.10
Fixed in
✓ 6.12.95 6.12.x ✓ 6.18.38 6.18.x ✓ 7.1.3 7.1.x ✓ 7.2

References

4 total

Frequently asked questions

  • What is CVE-2026-53394?

    CVE-2026-53394 is a High severity Linux kernel vulnerability with a CVSS score of 7.5 out of 10 , classified as a Memory Leak flaw (CWE-401) . It affects Linux kernel versions from 6.10 onward and has been patched in 6.12.95, 6.18.38, 7.1.3 and others. CVE-2026-53394 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-53394?

    CVE-2026-53394 has a CVSS score of 7.5 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H .

  • Is there a patch available for CVE-2026-53394?

    Yes. CVE-2026-53394 has been patched. Fixed versions include 6.12.95, 6.18.38, 7.1.3 and others. If you are running Linux kernel 6.10 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-53394 actively exploited?

    No. CVE-2026-53394 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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