CVE WatchOct 19, 2026

CVE-2025-39964

Linux Kernel Race Condition Vulnerability

CVSS

7.8

High

EPSS

1.6%

p75

KEV

YES

Sep 18, 2026

Exploit Today

0-100

Published: Oct 13, 2025 · Last modified: Oct 19, 2026 · CWE-362

EPSS · 30d

1.0%EPSS · 30 days1.6%

2026-10-012026-10-29

KEV catalog record

Product

Linux / Kernel

Vulnerability

Linux Kernel Race Condition Vulnerability

Added to KEV

Sep 18, 2026

Remediate by

Sep 21, 2026

Known ransomware use

Summary description

Linux Kernel contains a race condition vulnerability which allows concurrent writes to the same AF_ALG socket causing data to be unpredictably interleaved and creating inconsistencies in the socket's internal state.

Required action

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.

Notes

This vulnerability affects an open-source component, third-party library, protocol, or proprietary implementation that could be used by different products. For more information, please see: ; https://git.kernel.org/stable/c/0f28c4adbc4a97437874c9b669fd7958a8c6d6ce; https://git.kernel.org/stable/c/e4c1ec11132ec466f7362a95f36a506ce4dc08c9; https://git.kernel.org/stable/c/1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8; https://git.kernel.org/stable/c/7c4491b5644e3a3708f3dbd7591be0a570135b84; https://git.kernel.org/stable/c/9aee87da5572b3a14075f501752e209801160d3d; https://git.kernel.org/stable/c/45bcf60fe49b37daab1acee57b27211ad1574042; https://git.kernel.org/stable/c/1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 ; BOD 26-04: https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk ; Forensics Triage Requirements: https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk ; https://nvd.nist.gov/vuln/detail/CVE-2025-39964

Technical 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.

Official references

Related CVEs

CVECVSSEPSSKEVRExploitTitleMod.

CVE-2026-1180304.2 MED

5.5%

——2A flaw was found in the HOTP authentication mechanism of the keycloak-services component, which provides identity and access management services. The issue occurs because the system validates a one-time password and updates its internal counter in two separate steps without proper locking. An attacker with a users password could exploit this timing gap to use a single one-time code to log in multiple times simultaneously.1d CVE-2026-115402—

1.8%

——1OpenVPN ovpn-dco-win 0.6.5 through 2.8.13 allows unprivileged local users to cause a denial of service (system crash) via a race condition in the TCP connect path.2d CVE-2026-1181286.5 MED

29.5%

——9A vulnerability has been found in a2aproject a2a-js up to 1.1.0. Impacted is the function ResultManager.applyStatusUpdate of the file src/server/result_manager.ts of the component Task Status Update Handler. Such manipulation leads to race condition. The attack may be launched remotely. Upgrading to version 1.2.0 is recommended to address this issue. The name of the patch is 7b87c9480bfa643f9d2b2eaf06988b3d3a95de25. It is recommended to upgrade the affected component.2d CVE-2026-1175075.4 MED

27.8%

——8A security vulnerability has been detected in a2aproject a2a-java up to 1.2.0.Final. This impacts the function TaskManager.saveTaskEvent. The manipulation leads to race condition. The attack may be initiated remotely. Upgrading to version 1.3.0.Final will fix this issue. The identifier of the patch is 6b8e1e085c35e970ef0048901cd25850e4791ec2. The affected component should be upgraded.3d CVE-2026-1174993.7 LOW

0.6%

——0@fastify/session is a session plugin for Fastify. In all releases before 11.1.6, with the default rolling session behavior, a request that restored a session before a logout could save its own copy after another request had completed the session destroy call, recreating the destroyed session identifier with its authenticated data. An attacker who already holds a victim's valid signed session cookie and keeps a request in flight across the logout can replay that cookie to restore the session after it was meant to be revoked, without any cookie theft or signature forgery. The issue is fixed in @fastify/session 11.1.6, which adds a per session generation marker and a conditional store write so a session restored before a logout or regeneration cannot recreate or overwrite the current entry, and users should upgrade to 11.1.6 or later. There is no workaround, and custom session stores must implement the new conditional write.3d CVE-2026-1138964.7 MED

11.5%

——3A race condition was addressed with additional validation. This issue is fixed in iOS 26.7.2 and iPadOS 26.7.2, iOS 27.2 and iPadOS 27.2, macOS Golden Gate 27.2, macOS Sequoia 15.8.2, macOS Tahoe 26.7.2, visionOS 27.2. An app may be able to access sensitive user data.19h