Risk Letters

Exploited vulnerability

CVE-2026-53266

TLP:CLEAR

Linux Kernel Out-of-Bounds Write Vulnerability

Linux Kernel contains an out-of-bounds write vulnerability in the ebtables SNAT target which allows an ARP sender hardware address rewrite to write directly into a nonlinear socket-buffer fragment backed by a splice-imported file page. 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: 8.8
  • EPSS (probability of exploitation within 30 days): 0.9 %
  • 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-787
  • 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