CIPSO Option Offset Vulnerability in Linux Kernel

CVE-2026-99064

What is CVE-2026-99064?

A vulnerability exists in the Linux kernel related to the handling of CIPSO (Common IP Security Options) options. When the cipso_v4_skbuff_delattr() function removes CIPSO bytes, it fails to adjust the corresponding cached offsets for subsequent options correctly. This misalignment leads to incorrect parsing of network packet options, which may result in the interpretation of data as option length, potentially causing serious network communication errors. The issue affects how consumers like ip_forward_options() and __ip_options_echo() read packet options, highlighting the need for precise offset management to ensure data integrity in network operations. A fix has been implemented to adjust the cached offsets appropriately to mitigate the risk.

References