Vulnerability in Linux

CVE-2025-39931

In the Linux kernel, the following vulnerability has been resolved: crypto: af_alg - Set merge to zero early in af_alg_sendmsg If an error causes af_alg_sendmsg to abort, ctx->merge may contain a garbage value from the previous loop. This may then trigger a crash on the next entry into af_alg_sendmsg when it attempts to do a merge that can't be done. Fix this by setting ctx->merge to zero near the start of the loop.

EPSS: 0.001 (4.1th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-39931?
CVE-2025-39931 is a high-severity vulnerability in Linux, classified under Use of Uninitialized Resource. CVSS score: 7.8/10. Published 2025-10-04.
How severe is CVE-2025-39931?
High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-39931 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.