CVE-2025-39964KEV · OVERDUECWE-362

Linux Kernel Race Condition Vulnerability

High · published October 13, 2025

Patch now

Confirmed exploited, and the score agrees

CVSS calls it high at 7.8. It is confirmed in active exploitation. It sits in the 71.5th percentile for exploit probability.

33
days past CISA
deadline
CVSS v3.1
7.8
EPSS
1%
Percentile
71.5
In the wild
Confirmed
What it is

In the Linux kernel, the following vulnerability has been resolved:

crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg

Issuing two writes to the same af_alg socket is bogus as the

data will be interleaved in an unpredictable fashion. Furthermore,

concurrent writes may create inconsistencies in the internal

socket state.

Disallow this by adding a new ctx->write field that indiciates

exclusive ownership for writing.

The record
Technical detail
CVSS v3.1
7.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.01362 · 71.5th percentile
Weakness
CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Published
2025-10-13T18:15Z
KEV added
2026-09-18 · due 2026-09-21
Affected products (14)
ProductVersionsFixed in
linux/linux_kernel≥ 2.6.38, < 5.10.2455.10.245
linux/linux_kernel≥ 5.11, < 5.15.1945.15.194
linux/linux_kernel≥ 5.16, < 6.1.1546.1.154
linux/linux_kernel≥ 6.2, < 6.6.1086.6.108
linux/linux_kernel≥ 6.7, < 6.12.496.12.49
linux/linux_kernel≥ 6.13, < 6.16.96.16.9
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
linux/linux_kernelall versions—
siemens/simatic_s7-1500_cpu_1518-4_pn\/dp_mfp_firmware≥ 3.1.6—
siemens/simatic_s7-1500_cpu_1518f-4_pn\/dp_mfp_firmware≥ 3.1.6—
References (10)
EPSS history
Timeline
  • 13 OCT 13:48Z
    crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg
    cvelistv5