CVE-2026-53363: linux kernel vulnerability

CVE-2026-53363: critical vulnerability affecting linux kernel. Check CVSS, KEV status, business impact and recommended administrator actions.
CVE-2026-53363CVSS 9.8Linux

CVE-2026-53363: linux kernel vulnerability

CVE-2026-53363: critical vulnerability affecting linux kernel. Check CVSS, KEV status, business impact and recommended administrator actions.

CVSS
9.8 CRITICAL
EPSS
23.5%
Known exploited
not in KEV
Product
linux kernel

What is known

In the Linux kernel, the following vulnerability has been resolved: xfrm: iptfs: preserve shared-frag marker in iptfs_consume_frags() iptfs_consume_frags() transfers paged fragments from one socket buffer to another but fails to propagate the SKBFL_SHARED_FRAG flag. This is the same class of bug that was fixed in skb_try_coalesce() for CVE-2026-46300: when fragments backed by read-only page-cache pages are merged, the marker indicating their shared nature must be preserved so that ESP can decide correctly whether in-place encryption is safe. Apply the same two-line fix used in skb_try_coalesce() to iptfs_consume_frags().

Business impact

Successful exploitation of CVE-2026-53363, a critical vulnerability (CVSS 9.8) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

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