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CVE-2026-99064

Linux: cipso: adjust cached option offsets when removing CIPSO

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
NoneNot scored
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)No scoreNo FIRST EPSS score in this snapshot yet
Fixed in2200fe1d6148b78e1b8f00f4b2bd47760015077fAlso 6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0, 6d25ffca055a77787c21a36b66c253f76239411bCVE List
Published23 Oct 2026Updated 23 Oct 2026CVE List

What fixes it

  • 2200fe1d6148b78e1b8f00f4b2bd47760015077fLinuxCVE List
  • 6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0LinuxCVE List
  • 6d25ffca055a77787c21a36b66c253f76239411bLinuxCVE List

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

Description

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.

Text from CVE List

Affected versions 10

  • Linuxaffected: 89aa3619d141d6cfb6040a561aebb6d99d3e2285 before b965977126a90e01825814c859ba4788691eddd3CVE List
  • Linuxaffected: 89aa3619d141d6cfb6040a561aebb6d99d3e2285 before 2200fe1d6148b78e1b8f00f4b2bd47760015077fCVE List
  • Linuxaffected: 89aa3619d141d6cfb6040a561aebb6d99d3e2285 before 6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0CVE List
  • Linuxaffected: 89aa3619d141d6cfb6040a561aebb6d99d3e2285 before 6d25ffca055a77787c21a36b66c253f76239411bCVE List
  • Linuxaffected: 6.10CVE List
  • Linuxunaffected: all versions before 6.10CVE List
  • Linuxunaffected: 6.12.113 through 6.12.*CVE List
  • Linuxunaffected: 6.18.57 through 6.18.*CVE List
  • Linuxunaffected: 7.2.11 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 4