Linux Kernel up to 6.16.8 crypto af_alg_sendmsg state issue

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.16.8. Affected by this issue is the function af_alg_sendmsg of the component crypto. Executing a manipulation can lead to state issue. This vulnerability is registered as CVE-2025-39964. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.16.8. It has been declared as critical. This vulnerability affects the function af_alg_sendmsg of the component crypto. The manipulation with an unknown input leads to a state issue vulnerability. The CWE definition for the vulnerability is CWE-371. The impact remains unknown. CVE summarizes:

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 advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2025-39964 since 04/16/2025. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/03/2026).

The vulnerability scanner Nessus provides a plugin with the ID 271415 (Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2025-20719)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.245, 5.15.194, 6.1.154, 6.6.108, 6.12.49 or 6.16.9 eliminates this vulnerability. Applying the patch 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce/e4c1ec11132ec466f7362a95f36a506ce4dc08c9/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8/7c4491b5644e3a3708f3dbd7591be0a570135b84/9aee87da5572b3a14075f501752e209801160d3d/45bcf60fe49b37daab1acee57b27211ad1574042/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (271415) and CERT Bund (WID-SEC-2025-2268). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 3.3
NVD Vector: 🔒

CVSSv2info

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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: State issue
CWE: CWE-371
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 271415
Nessus Name: Oracle Linux 10 / 9 : Unbreakable Enterprise kernel (ELSA-2025-20719)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.245/5.15.194/6.1.154/6.6.108/6.12.49/6.16.9
Patch: 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce/e4c1ec11132ec466f7362a95f36a506ce4dc08c9/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8/7c4491b5644e3a3708f3dbd7591be0a570135b84/9aee87da5572b3a14075f501752e209801160d3d/45bcf60fe49b37daab1acee57b27211ad1574042/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285

Timelineinfo

04/16/2025 CVE reserved
10/13/2025 +180 days Advisory disclosed
10/13/2025 +0 days VulDB entry created
02/03/2026 +113 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39964 (🔒)
GCVE (CVE): GCVE-0-2025-39964
GCVE (VulDB): GCVE-100-328120
CERT Bund: WID-SEC-2025-2268 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 10/13/2025 16:24
Updated: 02/03/2026 15:42
Changes: 10/13/2025 16:24 (59), 10/15/2025 04:43 (7), 10/25/2025 13:33 (2), 11/21/2025 04:51 (1), 12/22/2025 04:02 (1), 02/03/2026 15:42 (11)
Complete: 🔍
Cache ID: 216::103

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