{"id":"CVE-2026-99064","state":"PUBLISHED","title":"cipso: adjust cached option offsets when removing CIPSO","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ncipso: adjust cached option offsets when removing CIPSO\n\ncipso_v4_skbuff_delattr() removes the CIPSO bytes but does not adjust\ncached offsets for options that follow them.\n\nFor example, with a valid 10-byte CIPSO option followed by a seven-byte\nRR option, parsing records rr at offset 30.  Removing CIPSO moves RR to\noffset 20, while the cached offset remains 30.  Consumers such as\nip_forward_options() and __ip_options_echo() then access the wrong bytes;\nthe latter may interpret packet data as the option length and copy it into\nfixed-size option storage.\n\nMirror cipso_v4_delopt() and subtract cipso_len from the srr, rr, ts and\nrouter_alert offsets when they follow CIPSO.  cipso_len is the distance\nthe first memmove() shifts those options.  The later header move and\nnetwork-header reset relocate the bytes and their offset base together.","publishedAt":"2026-10-23T12:23:05.854Z","updatedAt":"2026-10-24T14:10:17.979Z","severity":{"score":8.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"b965977126a90e01825814c859ba4788691eddd3","versionType":"git"},{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"2200fe1d6148b78e1b8f00f4b2bd47760015077f","versionType":"git"},{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0","versionType":"git"},{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"6d25ffca055a77787c21a36b66c253f76239411b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/cipso_ipv4.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/cipso_ipv4.c"]}],"references":["https://git.kernel.org/stable/c/b965977126a90e01825814c859ba4788691eddd3","https://git.kernel.org/stable/c/2200fe1d6148b78e1b8f00f4b2bd47760015077f","https://git.kernel.org/stable/c/6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0","https://git.kernel.org/stable/c/6d25ffca055a77787c21a36b66c253f76239411b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99064.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99064","state":"PUBLISHED","datePublished":"2026-10-23T12:23:05.854Z","dateUpdated":"2026-10-24T14:10:17.979Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.389Z"},"containers":{"cna":{"title":"cipso: adjust cached option offsets when removing CIPSO","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncipso: adjust cached option offsets when removing CIPSO\n\ncipso_v4_skbuff_delattr() removes the CIPSO bytes but does not adjust\ncached offsets for options that follow them.\n\nFor example, with a valid 10-byte CIPSO option followed by a seven-byte\nRR option, parsing records rr at offset 30.  Removing CIPSO moves RR to\noffset 20, while the cached offset remains 30.  Consumers such as\nip_forward_options() and __ip_options_echo() then access the wrong bytes;\nthe latter may interpret packet data as the option length and copy it into\nfixed-size option storage.\n\nMirror cipso_v4_delopt() and subtract cipso_len from the srr, rr, ts and\nrouter_alert offsets when they follow CIPSO.  cipso_len is the distance\nthe first memmove() shifts those options.  The later header move and\nnetwork-header reset relocate the bytes and their offset base together."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"b965977126a90e01825814c859ba4788691eddd3","versionType":"git"},{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"2200fe1d6148b78e1b8f00f4b2bd47760015077f","versionType":"git"},{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0","versionType":"git"},{"version":"89aa3619d141d6cfb6040a561aebb6d99d3e2285","status":"affected","lessThan":"6d25ffca055a77787c21a36b66c253f76239411b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/cipso_ipv4.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.113","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.11","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv4/cipso_ipv4.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/b965977126a90e01825814c859ba4788691eddd3"},{"url":"https://git.kernel.org/stable/c/2200fe1d6148b78e1b8f00f4b2bd47760015077f"},{"url":"https://git.kernel.org/stable/c/6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0"},{"url":"https://git.kernel.org/stable/c/6d25ffca055a77787c21a36b66c253f76239411b"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":8.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - A remote peer can send an IPv4 datagram containing valid CIPSO followed by RR/TS; ip_rcv()->ip_rcv_options() caches their wire offsets, then selinux_ip_forward()->netlbl_skbuff_setattr()->cipso_v4_skbuff_delattr() removes CIPSO without rebasing them.\nAC:H - The strongest path requires a CONFIG_NETLABEL/SELinux forwarding gateway with network_peer_controls, a recognized CIPSO DOI, an UNLABELED egress mapping, and a later FORWARD REJECT invoking nf_send_unreach(); these non-default conditions are outside the sender's control.\nPR:N - __ip_options_compile() applies CAP_NET_RAW only when skb is NULL; received packets undergo cipso_v4_validate() and SELinux label-policy checks, but require no peer authentication, victim credentials, or target-side privileges.\nUI:N - After the datagram arrives, ip_rcv(), SELinux FORWARD relabeling, and nf_send_unreach()->__ip_options_echo() execute entirely in kernel packet handling without any victim action.\nS:U - The overwrite occurs in __ip_options_echo()'s in-kernel reply-option storage and can compromise the same host kernel; it crosses no VM, IOMMU, or separate security-authority boundary.\nC:H - With stale opt->rr pointing into payload, __ip_options_echo() takes an attacker-chosen length and source bytes and copies up to 255 bytes into 40-byte replyopts.opt.__data; control-flow compromise from this stack overwrite can expose arbitrary kernel memory.\nI:H - The memcpy() can place 255 attacker-controlled payload bytes into the 40-byte stack destination, crossing the stack canary and saved return address in the demonstrated x86-64 layout and enabling kernel control-flow hijacking.\nA:H - The 255-byte __ip_options_echo() stack overwrite triggers KASAN or the stack canary and can panic the kernel; the packet-processing path can be invoked repeatedly with crafted IPv4 datagrams."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-24T14:10:17.979Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.12.113"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"7.2.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}