CVE-2025-39682 — Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability
Linux Kernel contains an improper check for unusual or exceptional conditions vulnerability in the TLS receive path which allows a zero-length record retrieved from the rx_list to bypass the intended recvmsg() record-type handling, potentially causing subsequent TLS records to be processed using incorrect zero-copy and queuing assumptions. The impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to
Platform
Ubuntu Server
CVE Record
CVE-2025-39682
Advisory
CISA-KEV
Published
18 September 2026
Views
23
Primary source: Review the official advisory at nvd.nist.gov
Go to Source
Status
This vulnerability appears in CISA's catalog of known exploited vulnerabilities. It is not a theoretical risk — it is being used in the wild.
Description
Linux Kernel contains an improper check for unusual or exceptional conditions vulnerability in the TLS receive path which allows a zero-length record retrieved from the rx_list to bypass the intended recvmsg() record-type handling, potentially causing subsequent TLS records to be processed using incorrect zero-copy and queuing assumptions. The impacted product(s) could be end-of-life (EoL) and/or end-of-service (EoS). Users are advised to discontinue use and/or transition to a supported version.
Details
Vendor: Linux
Product: Kernel
Added to catalog: 2026-09-18
Action Required by CISA
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.
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