CVE-2025-39931

Updated on 04 Oct 2025

Severity

5.5 Medium severity

Details

CVSS score
5.5
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Overview

About vulnerability

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.

Details

Affected packages:
kernel @ 4.18.0 (+13 more)

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.

Fixes