CVE entry · CVE-2026-53266
CVE-2026-53266: 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.
- Actively exploited: added to CISA’s KEV catalog on September 18, 2026.
- Use by ransomware: not established so far.
- Remediation deadline for US federal agencies: September 21, 2026.
Description from CISA’s KEV catalog.
What to do
- Check whether your estate includes Linux Kernel, including internet-facing devices.
- Apply the vendor’s patch or mitigations (references below). Failing that, isolate the product or stop using it, as CISA requires of US federal agencies.
- An exploited vulnerability has often been used before it was fixed: look for signs of compromise, especially on internet-facing devices.
References
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- Vendor advisory or reference cited by CISA (git.kernel.org)
- NVD entry (NIST)
- CISA KEV catalog
Other Linux vulnerabilities
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Linux Kernel Race Condition Vulnerability
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Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability
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Linux Kernel Unspecified Vulnerability
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Linux Kernel Out-of-Bounds Write Vulnerability
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Linux Kernel Improper Authentication Vulnerability
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Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability