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CVE-2026-53266

Linux Kernel Out-of-Bounds Write Vulnerability

Linux KernelOperating systems
Open in ThreatlineRecord JSON
CVSS
8.8High
ExploitationExploited in the wildAdded to KEV 18 Sep 2026CISA KEV
Exploit odds (EPSS)0.83%Chance of exploitation activity in the next 30 days, higher than 57% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in76280b78cc9f23bdc6438e10ad6dff148ef8375bAlso 153ea96c806aea395daba907a4f88480b6ad5093, 67ba971ae02514d85818fe0c32549ab4bfa3bf49 and 3 moreCVE List
Federal deadline21 Sep 2026Remediation due date for US federal agenciesCISA KEV
CISA required actionApply 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. CISA KEV
Patching is not enoughCISA requires federal agencies to look for signs of compromise on affected systems, not only patch (forensic triage under BOD 26-04). Treat exposed systems as possibly compromised. CISA guidance

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Timeline

  1. 25 Jun 2026, 08:39 UTCPublishedCVE List
  2. 18 Sep 2026Added to CISA KEVCISA KEV

Description

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.

Text from CVE List

Affected versions 24

  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before bf84ad7c7a9ede46e31afaa41a1ba06a159e8c87CVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before 76280b78cc9f23bdc6438e10ad6dff148ef8375bCVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before b7e91939ba9be805a62a257fa4e227dffbb88fa0CVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before afd64b59c3de9bbbdd3759e834fdc55cda716e0bCVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before 153ea96c806aea395daba907a4f88480b6ad5093CVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before b18675263db1147c8e1cab625400c13a0d87bd2dCVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before c9b5ff59feffb92a147a84a5aa28acd2cb8ff4c5CVE List
  • Linuxaffected: 63137bc5882a1882c553d389fdeeeace86ee1741 before 67ba971ae02514d85818fe0c32549ab4bfa3bf49CVE List
  • Linuxaffected: 2f3839075a5f8dcf116c1abe35b36b018ac62445CVE List
  • Linuxaffected: 51ba2945a8ef65ae437c8f9ba05f0343aa82ae5bCVE List
  • Linuxaffected: b7d23c2c87584eb429f115c078ed511be8b18e29CVE List
  • Linuxaffected: 5.4.73 before 5.5CVE List
  • Linuxaffected: 5.8.17 before 5.9CVE List
  • Linuxaffected: 5.9.2 before 5.10CVE List
  • Linuxaffected: 5.10CVE List
  • Linuxunaffected: all versions before 5.10CVE List
  • Linuxunaffected: 5.10.259 through 5.10.*CVE List
  • Linuxunaffected: 5.15.210 through 5.15.*CVE List
  • Linuxunaffected: 6.1.176 through 6.1.*CVE List
  • Linuxunaffected: 6.6.143 through 6.6.*CVE List
  • Linuxunaffected: 6.12.94 through 6.12.*CVE List
  • Linuxunaffected: 6.18.36 through 6.18.*CVE List
  • Linuxunaffected: 7.0.13 through 7.0.*CVE List
  • Linuxunaffected: 7.1CVE List

References 10