CVE-2025-39964

Aliases:UBUNTU-CVE-2025-39964DEBIAN-CVE-2025-39964CGA-243h-p34v-2r53CGA-2jgg-fxrh-jw2mCGA-2rr7-4rhj-q8f6CGA-45fm-x95j-wgjhCGA-5pm4-r359-56x9CGA-6w84-mgvc-rfv7CGA-86wf-c389-mc9vCGA-8c8r-7cm8-rpx5CGA-9g2w-qc4r-7455CGA-c9v5-56f5-mj83CGA-cq8v-m98v-r794CGA-fjw9-hq23-7f83CGA-g447-vmcf-j3vcCGA-ggx2-697c-p2xgCGA-ghhq-g7gv-xgcxCGA-hpfh-xm84-83vwCGA-j6hh-jgqh-rmchCGA-m36w-6gr3-rpwqCGA-m45w-fprj-8rm7CGA-mcf7-f365-4mh5CGA-qjgg-356f-6jm7CGA-rqv5-rf45-852xCGA-rrf8-jhrf-p5wgCGA-v4gq-2r74-hhx9CGA-vc7w-9gxc-cg5jCGA-vg7x-mwqf-4xp8CGA-x7c8-mqcv-ccv7CGA-xxmw-q78c-3qwj
Advisory lineage Upstream: 0 Downstream: 63
Analyzed
Published: 13 Oct 2025, 13:48
Last modified:19 Sept 2026, 03:56

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.32% LOW
0% probability +0.27%
KEV
Listed
CISA
1 listing
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

13 Oct 2025, 13:48
Published
Vulnerability first disclosed
18 Sept 2026, 00:00
Added to CISA KEV
Linux Kernel Race Condition Vulnerability
19 Sept 2026, 03:56
Last Modified
Vulnerability information updated
21 Sept 2026, 00:00
CISA Remediation Due
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Description

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.

CVSS Metrics

  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • v3.1•LOW•Score: 3.3CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

EPSS Trends

Current EPSS score: 0.32%• Percentile: 26%

Techniques & Countermeasures

  • CWE-362•Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

    The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Systems

  • chainguard•linux-aws-6.12

    < 6.12.76-r0

  • chainguard•linux-aws-6.18

    < 6.18.17-r0

  • chainguard•linux-azure-6.12

    < 6.12.76-r0

  • chainguard•linux-azure-6.18

    < 6.18.17-r0

  • chainguard•linux-desktop-6.18

    < 6.18.48-r0

  • chainguard•linux-desktop-7.2

    < 7.2.3-r0

  • chainguard•linux-firecracker-6.18

    < 6.18.44-r0

  • chainguard•linux-gcp-6.12

    < 6.12.76-r0

  • chainguard•linux-gcp-6.18

    < 6.18.17-r0

  • chainguard•linux-qemu-6.12

    < 6.12.76-r0

  • chainguard•linux-qemu-6.18

    < 6.18.17-r0

  • chainguard•linux-qemu-melange

    < 6.18.17-r0

  • chainguard•linux-raspberry-pi

    < 20260609-r0

  • chainguard•linux-raspberry-pi-4

    < 20260911-r0

  • chainguard•linux-vmware-6.12

    < 6.12.76-r0

  • chainguard•linux-vmware-6.18

    < 6.18.17-r0

  • debian•linux

    < 5.10.247-1 | < 6.1.158-1 | < 6.12.57-1 | < 6.16.9-1

  • debian•linux-6.1

    < 6.1.158-1~deb11u1

  • ubuntu•linux

    all | < 4.4.0-276.310 | < 4.15.0-245.257 | < 5.4.0-224.244 | < 5.15.0-164.174 | < 6.8.0-90.91

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    < 4.4.0-1150.156 | < 4.4.0-1188.203 | < 4.15.0-1187.200 | < 5.4.0-1153.163 | < 5.15.0-1098.105 | < 6.8.0-1044.46

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1098.105~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1153.163~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.14

    < 6.14.0-1018.18~24.04.1

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1044.46~22.04.1

  • ubuntu•linux-aws-fips

    < 4.15.0-2125.131 | all | < 5.4.0-1153.163+fips1 | < 5.15.0-1098.105+fips1 | < 6.8.0-1044.46+fips1

  • ubuntu•linux-aws-hwe

    < 4.15.0-1187.200~16.04.1

  • ubuntu•linux-azure

    < 4.15.0-1195.210~14.04.1 | < 4.15.0-1195.210~16.04.1 | all | < 5.4.0-1156.163 | < 5.15.0-1102.111 | < 6.8.0-1044.50

  • ubuntu•linux-azure-4.15

    < 4.15.0-1195.210

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1102.111~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1156.163~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    all

  • ubuntu•linux-azure-6.14

    < 6.14.0-1017.17~24.04.1

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1044.50~22.04.1

  • ubuntu•linux-azure-edge

    all

Showing first 50 affected entries in server-rendered view.

References (46)