{"schema":"threatline.record/2","record":{"id":"CVE-2026-99041","aliases":[],"summary":"ip6_gre: remove obsolete ERSPAN PMTU update","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nip6_gre: remove obsolete ERSPAN PMTU update\n\nA tc tunnel_key action can attach a METADATA_IP_TUNNEL dst to an skb,\nand mirred can redirect it to a native ip6erspan device. The legacy PMTU\nupdate in ip6erspan_tunnel_xmit() treats that metadata dst as a route.\nSince it has no output device, dst_dev(dst)->mtu dereferences NULL.\n\nOn v7.2 with KASAN, an initial UID/GID 65534 process with CapEff 0 used\nself-created user and network namespaces to trigger:\n\n  KASAN: null-ptr-deref\n  RIP: ip6erspan_tunnel_xmit+0x10fc/0x2cc0\n  Kernel panic - not syncing: Fatal exception in interrupt\n\nThe update is obsolete. Commit fe1a4ca0a2b7 (\"ip6_gre: process toobig\nin a better way\") changed IPv6 GRE Too Big handling to update the\nunderlay route and removed the equivalent block from __gre6_xmit().\nip6_tnl_xmit() then propagates the underlay PMTU to the overlay route.\n\nRemove the stale ERSPAN copy and its now-unused dst variable. This\neliminates the metadata-dst dereference and keeps ERSPAN aligned with\nIPv6 GRE PMTU handling.","categories":["Operating systems"],"product":"Linux","vendor":"Linux","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99041","source_modified_at":"2026-10-23T12:22:00.403Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"Linux","vendor":"Linux","versions":[{"version":"5a963eb61b7c39e6c422b6e48619d19d04719358","lessThan":"b14a682ad7d45345701e08f9279d483a1da8b36c","status":"affected","versionType":"git"},{"version":"5a963eb61b7c39e6c422b6e48619d19d04719358","lessThan":"f5b143f4cd3fb7673df8d727550478a4b762908a","status":"affected","versionType":"git"},{"version":"5a963eb61b7c39e6c422b6e48619d19d04719358","lessThan":"2d06cb25a497d3a7034ef9d172626c2d6620a0f1","status":"affected","versionType":"git"},{"version":"5a963eb61b7c39e6c422b6e48619d19d04719358","lessThan":"8f27260b989f488760289276377db24fbfb20bfa","status":"affected","versionType":"git"},{"version":"5a963eb61b7c39e6c422b6e48619d19d04719358","lessThan":"8bc60db48e8cba35488bbd6e1f94aa990afa275a","status":"affected","versionType":"git"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99041","source_modified_at":"2026-10-23T12:22:00.403Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"Linux","vendor":"Linux","versions":[{"version":"4.16","status":"affected"},{"version":"0","lessThan":"4.16","status":"unaffected","versionType":"semver"},{"version":"6.6.160","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.114","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.58","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.11","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}],"defaultStatus":"affected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99041","source_modified_at":"2026-10-23T12:22:00.403Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Linux","ecosystem":null},"version":"2d06cb25a497d3a7034ef9d172626c2d6620a0f1","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99041","source_modified_at":"2026-10-23T12:22:00.403Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Linux","ecosystem":null},"version":"8f27260b989f488760289276377db24fbfb20bfa","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-99041","source_modified_at":"2026-10-23T12:22:00.403Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"Linux","ecosystem":null},"version":"8bc60db48e8cba35488bbd6e1f94aa990afa275a","basis":"first unaffected version stated in the CVE record"}],"cvss":null,"severity":null,"kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-23T12:22:00.403Z","modified_at":"2026-10-23T12:22:00.403Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-99041","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T12:22:00.403Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://git.kernel.org/stable/c/b14a682ad7d45345701e08f9279d483a1da8b36c"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/f5b143f4cd3fb7673df8d727550478a4b762908a"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/2d06cb25a497d3a7034ef9d172626c2d6620a0f1"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/8f27260b989f488760289276377db24fbfb20bfa"},{"source":"CVE List","url":"https://git.kernel.org/stable/c/8bc60db48e8cba35488bbd6e1f94aa990afa275a"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":"product","confidence":"heuristic","reviewed":false},"change_timestamp":"2026-10-23T12:22:00.403Z","content_hash":"dee4087381423d2c55413aed7339565fe372f5ec122267f7376672aadf22ef95"}}