Use After Free in Linux

CVE-2025-38724

In the Linux kernel, the following vulnerability has been resolved: nfsd: handle get_client_locked() failure in nfsd4_setclientid_confirm() Lei Lu recently reported that nfsd4_setclientid_confirm() did not check the return value from get_client_locked(). a SETCLIENTID_CONFIRM could race with a confirmed client expiring and fail to get a reference. That could later lead to a UAF. Fix this by getting a reference early in the case where there is an extant confirmed client. If that fails then treat it as if there were no confirmed client found at all. In the case where the unconfirmed client is expiring, just fail and return the result from get_client_locked().

Vulnerability class: Use-After-Free

EPSS: 0.002 (5.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-38724?
CVE-2025-38724 is a critical-severity vulnerability in Linux, classified under Use After Free. CVSS score: 9.8/10. Published 2025-09-04.
How severe is CVE-2025-38724?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-38724 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.