CVE-2026-99064

In the Linux kernel, the following vulnerability has been resolved:

cipso: adjust cached option offsets when removing CIPSO

cipso v4 skbuff delattr() removes the CIPSO bytes but does not adjust cached offsets for options that follow them.

For example, with a valid 10-byte CIPSO option followed by a seven-byte RR option, parsing records rr at offset 30. Removing CIPSO moves RR to offset 20, while the cached offset remains 30. Consumers such as ip forward options() and ip options echo() then access the wrong bytes; the latter may interpret packet data as the option length and copy it into fixed-size option storage.

Mirror cipso v4 delopt() and subtract cipso len from the srr, rr, ts and router alert offsets when they follow CIPSO. cipso len is the distance the first memmove() shifts those options. The later header move and network-header reset relocate the bytes and their offset base together.