— Unscored

Linux Kernel Race Condition Vulnerability

CVE-2025-39964 Exploited

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

Being exploited in the wild

Catalogued 18 September 2026 · US federal remediation deadline 21 September 2026

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…

Exploit code is also public: Public PoC

Public PoCn1k0oowang/CVE-2025-39964_EXP3 stars
Public PoCsuominen/CVE-2025-39964

Assessment

CVSS: Not yet scored
Severity: Unscored
Known exploited: Yes — listed in the CISA KEV catalog
Exploit availability: CISA KEV, Public PoC
Published: 18 September 2026
Last updated: 18 September 2026
Affected: Linux · Kernel
Weakness: CWE-362

At the source

CISA KEV

References

https://www.cisa.gov/known-exploited-vulnerabilities-catalog

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Query this programmatically

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