Description
In the Linux kernel, the following vulnerability has been resolved:

NFS: Pin the 'struct nfs_server' during a FREE_STATEID call

Dan Aloni reports that he was able to hit a use-after-free bug if a
FREE_STATEID operation gets delayed for whatever reason. Fix this by
bumping the refcount of the 'struct nfs_server' object for the duration
of the FREE_STATEID so it doesn't get cleaned up from underneath us
while operations are still in flight.
Published: 2026-08-22
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: Use-After-Free in NFS server that could lead to arbitrary code execution
Action: Apply Patch
AI Analysis

Impact

A use-after-free bug is triggered during an NFS FREE_STATEID operation. If the operation is delayed, the kernel may free the 'struct nfs_server' while it is still in use, allowing an attacker to manipulate memory and potentially execute arbitrary code or corrupt data. The weakness corresponds to the CWE-911 weakness.

Affected Systems

All Linux kernel implementations that have not yet applied the patch that bumps the reference count during FREE_STATEID are affected. The CVE does not specify particular kernel releases, so any installation running the unpatched kernel on a system that exposes NFS services is at risk.

Risk and Exploitability

The CVSS score is 9.8, EPSS is < 1%, and the vulnerability is not listed in the CISA KEV catalog. The likely attack vector would involve an attacker with access to trigger a delayed FREE_STATEID, such as a privileged NFS client or administrator. Exploitation could lead to arbitrary code execution or system compromise, but the low exploitation probability indicates the risk is moderate but not negligible.

Generated by OpenCVE AI on August 25, 2026 at 07:51 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply a kernel update that includes the patch to bump the reference count of the nfs_server during FREE_STATEID
  • Restart the NFS service after updating the kernel to ensure the new reference counting is active
  • Until a patch is available, restrict or disable NFS services from untrusted clients to reduce exposure

Generated by OpenCVE AI on August 25, 2026 at 07:51 UTC.

Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4777-1 linux security update
Debian DSA Debian DSA DSA-6466-1 linux security update
History

Tue, 25 Aug 2026 06:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Mon, 24 Aug 2026 14:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Mon, 24 Aug 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-911
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Sat, 22 Aug 2026 18:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Sat, 22 Aug 2026 15:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: NFS: Pin the 'struct nfs_server' during a FREE_STATEID call Dan Aloni reports that he was able to hit a use-after-free bug if a FREE_STATEID operation gets delayed for whatever reason. Fix this by bumping the refcount of the 'struct nfs_server' object for the duration of the FREE_STATEID so it doesn't get cleaned up from underneath us while operations are still in flight.
Title NFS: Pin the 'struct nfs_server' during a FREE_STATEID call
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-25T05:42:09.527Z

Reserved: 2026-08-15T05:44:03.930Z

Link: CVE-2026-74730

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-22T16:16:48.137

Modified: 2026-08-25T06:18:59.463

Link: CVE-2026-74730

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-08-22T00:00:00Z

Links: CVE-2026-74730 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-25T08:00:13Z

Weaknesses
  • CWE-911

    Improper Update of Reference Count