Use After Free in Linux

CVE-2025-21923

In the Linux kernel, the following vulnerability has been resolved: HID: hid-steam: Fix use-after-free when detaching device When a hid-steam device is removed it must clean up the client_hdev used for intercepting hidraw access. This can lead to scheduling deferred work to reattach the input device. Though the cleanup cancels the deferred work, this was done before the client_hdev itself is cleaned up, so it gets rescheduled. This patch fixes the ordering to make sure the deferred work is properly canceled.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (9.5th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 10th percentile — 9.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2025-21923: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Linux — versions e1147961b2145fa61c3078a4a797d9576cde91ab, 3e38cbbfa0a128a9d64773240a9eb3bc7bae3b1a, 053fa3888d2a957f4db26c05e503f4c6b9570a30
  • Linux Kernel

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-21923?
CVE-2025-21923 is a high-severity vulnerability in Linux, classified under Use After Free. CVSS score: 7.8/10. Published 2025-04-01.
How severe is CVE-2025-21923?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-21923 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.