# CVE-2026-74730: Linux kernel NFS use-after-free in FREE_STATEID

Source: https://junglewise.ai/threats/cve-2026-74730-linux-kernel-nfs-use-after-free-in-free-stateid  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-22. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-74730 · Severity: critical · CVSS 9.8 · Published 2026-08-22

A use-after-free vulnerability exists in the Linux kernel's NFS (Network File System) implementation during FREE_STATEID operations. When a FREE_STATEID call is delayed, the kernel can attempt to access server structures that have already been cleaned up, potentially causing a system crash or allowing an attacker with network access to trigger a denial of service against NFS servers.

Technologies: [Linux Kernel](https://junglewise.ai/threats/technologies/kernel). Vendors: [Linux](https://junglewise.ai/threats/vendors/linux).

## Quick answers

**Is CVE-2026-74730 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-74730 being exploited in the wild.

**How severe is CVE-2026-74730?** Critical severity, with a CVSS score of 9.8, published 22 August 2026.

**Which products and versions are affected?** Linux Kernel multiple versions (see NVD for full list).

**Is there a fix for CVE-2026-74730?** A patch was published on 2026-06-30: Upstream commit cf616096a0f3a2b60f7d68b6b39674a6867ded9c by Anna Schumaker Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-74730 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2026-74730?** Check whether you run Linux Kernel at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a use-after-free bug in the NFS v4 protocol handler (fs/nfs/nfs4proc.c), specifically in the nfs41_free_stateid() function. The root cause is that the 'struct nfs_server' reference is not pinned during asynchronous FREE_STATEID RPC operations; if the operation is delayed, the server structure can be deallocated while the RPC is still in flight. The fix increments the reference count of the nfs_server object at the start of FREE_STATEID (via nfs_sb_active()) and decrements it during cleanup (via nfs_sb_deactive()), ensuring the structure remains valid for the duration of the operation. The attack vector is network-based and requires the ability to trigger or delay NFS operations; no authentication is required beyond standard NFS access.

## Affected products

- Linux Linux kernel multiple versions (see NVD for full list)

## Timeline

- 2026-08-22: disclosed
- 2026-06-30: patched: Upstream commit cf616096a0f3a2b60f7d68b6b39674a6867ded9c by Anna Schumaker

## References

- [https://git.kernel.org/stable/c/80ed3d762628b36c9e4b22fac7c65b72ef3b13dd](https://git.kernel.org/stable/c/80ed3d762628b36c9e4b22fac7c65b72ef3b13dd)
- [https://git.kernel.org/stable/c/af62f1af182d33a0de38308c012841885d8ab92e](https://git.kernel.org/stable/c/af62f1af182d33a0de38308c012841885d8ab92e)

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