Risk Letters

Exploited vulnerability

CVE-2025-39682

TLP:CLEAR

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 a supported version.

Facts

  • Vendor: Linux
  • Product: Kernel
  • CVSS: 9.8
  • EPSS (probability of exploitation within 30 days): 3.3 %
  • On CISA's Known Exploited Vulnerabilities list since: 18 September 2026
  • First known exploitation: 18 September 2026
  • CISA's deadline for US federal agencies: 21 September 2026
  • Weakness: CWE-754
  • First seen by Risk Letters: 18 September 2026

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Data: NVD (public domain), CISA KEV, FIRST EPSS, MITRE ATT&CK, AlienVault OTX. NVD