{"api_version":"1","generated_at":"2026-09-03T05:16:16+00:00","cve":"CVE-2026-72429","urls":{"html":"https://cve.report/CVE-2026-72429","api":"https://cve.report/api/cve/CVE-2026-72429.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72429","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72429"},"summary":{"title":"ipv6: ioam: fix type confusion of dst_entry","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix type confusion of dst_entry\n\nIOAM uses a dummy dst_entry(null_dst) to mark that the destination should\nnot be changed after the transformation. This dst is stored in the IOAM lwt\nstate and may be passed to dst_cache_set_ip6().\n\nHowever, the IPv6 dst cache path eventually calls rt6_get_cookie(), which\ntreats the dst_entry as part of a struct rt6_info. Since the null_dst was\nembedded directly as a struct dst_entry in struct ioam6_lwt, this resulted\nin an invalid cast and rt6_get_cookie() reading fields from the wrong\nobject.\n\nIn practice, the wrong cookie is not used while dst->obsolete is zero, but\nrt6_get_cookie() may also access per-cpu value when rt->sernum is\nzero. In this case, rt->sernum aliases ioam6_lwt::cache::reset_ts, which\ncan become zero, making this a potential invalid pointer access.\n\nFix this by embedding a full struct rt6_info for the dummy IPv6 route and\npassing its dst member to the dst APIs.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:22:16","updated_at":"2026-08-17 06:19:10"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"9.8","severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/9ed19e11d2146076d117d51a940643990118449b","name":"https://git.kernel.org/stable/c/9ed19e11d2146076d117d51a940643990118449b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5a3b2ee1e96d0580a8ed8deda6dfa430604f9ab0","name":"https://git.kernel.org/stable/c/5a3b2ee1e96d0580a8ed8deda6dfa430604f9ab0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ea24f911ead85ba3d570a31e37c52b6c949f6928","name":"https://git.kernel.org/stable/c/ea24f911ead85ba3d570a31e37c52b6c949f6928","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72429","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72429","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47ce7c854563fe8450e9cb8dcd62c6470e28076b ea24f911ead85ba3d570a31e37c52b6c949f6928 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47ce7c854563fe8450e9cb8dcd62c6470e28076b 5a3b2ee1e96d0580a8ed8deda6dfa430604f9ab0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 47ce7c854563fe8450e9cb8dcd62c6470e28076b 9ed19e11d2146076d117d51a940643990118449b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72429","cve":"CVE-2026-72429","epss":"0.006050000","percentile":"0.461060000","score_date":"2026-08-17","updated_at":"2026-08-18 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the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix type confusion of dst_entry\n\nIOAM uses a dummy dst_entry(null_dst) to mark that the destination should\nnot be changed after the transformation. This dst is stored in the IOAM lwt\nstate and may be passed to dst_cache_set_ip6().\n\nHowever, the IPv6 dst cache path eventually calls rt6_get_cookie(), which\ntreats the dst_entry as part of a struct rt6_info. Since the null_dst was\nembedded directly as a struct dst_entry in struct ioam6_lwt, this resulted\nin an invalid cast and rt6_get_cookie() reading fields from the wrong\nobject.\n\nIn practice, the wrong cookie is not used while dst->obsolete is zero, but\nrt6_get_cookie() may also access per-cpu value when rt->sernum is\nzero. In this case, rt->sernum aliases ioam6_lwt::cache::reset_ts, which\ncan become zero, making this a potential invalid pointer access.\n\nFix this by embedding a full struct rt6_info for the dummy IPv6 route and\npassing its dst member to the dst APIs."}],"metrics":[{"cvssV3_1":{"baseScore":9.8,"baseSeverity":"CRITICAL","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - The flaw is in ioam6_output() on the IPv6 transmit path (lwtunnel_output→dst_output), reachable when remotely sourced IPv6 packets are forwarded or locally output through an IOAM6 LWT route on internet-facing or LAN routers.\nAC:L - Once IOAM6 LWT inline routes exist, an attacker can reliably trigger the null_dst dst_cache_set_ip6() path by sending IPv6 traffic that misses the per-CPU dst cache, without races or uncontrollable memory layout.\nPR:N - Exploitation requires only the ability to send IPv6 packets; IOAM6 LWT route and namespace setup needs CAP_NET_ADMIN on the victim but is an operator deployment prerequisite, not attacker privilege.\nUI:N - No victim user action is required beyond normal network operation; crafted or high-volume IPv6 packets alone drive the vulnerable output path.\nS:U - Impact is kernel memory corruption and crash within the host kernel; it does not cross VM, container, or IOMMU security boundaries.\nC:H - Type confusion makes rt6_get_cookie() treat ioam6_lwt fields as rt6_info members and chase a misinterpreted fib6_info pointer via fib6_get_cookie_safe(), enabling out-of-bounds kernel memory reads.\nI:H - Casting a standalone dst_entry to rt6_info is type confusion that corrupts pointer interpretation and dst_cache cookie state, a class exploitable toward arbitrary kernel writes or control-flow hijack.\nA:H - The confused rt6_info layout can dereference invalid fib6_info/fib6_node pointers, causing kernel oops or panic; memory corruption in the networking fast path also risks host-wide denial of service."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:44:08.737Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/ea24f911ead85ba3d570a31e37c52b6c949f6928"},{"url":"https://git.kernel.org/stable/c/5a3b2ee1e96d0580a8ed8deda6dfa430604f9ab0"},{"url":"https://git.kernel.org/stable/c/9ed19e11d2146076d117d51a940643990118449b"}],"title":"ipv6: ioam: fix type confusion of dst_entry","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72429","datePublished":"2026-08-15T05:56:45.530Z","dateReserved":"2026-08-09T03:40:39.928Z","dateUpdated":"2026-08-17T05:44:08.737Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:22:16","lastModifiedDate":"2026-08-17 06:19:10","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72429","Ordinal":"1","Title":"ipv6: ioam: fix type confusion of dst_entry","CVE":"CVE-2026-72429","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72429","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: ioam: fix type confusion of dst_entry\n\nIOAM uses a dummy dst_entry(null_dst) to mark that the destination should\nnot be changed after the transformation. This dst is stored in the IOAM lwt\nstate and may be passed to dst_cache_set_ip6().\n\nHowever, the IPv6 dst cache path eventually calls rt6_get_cookie(), which\ntreats the dst_entry as part of a struct rt6_info. Since the null_dst was\nembedded directly as a struct dst_entry in struct ioam6_lwt, this resulted\nin an invalid cast and rt6_get_cookie() reading fields from the wrong\nobject.\n\nIn practice, the wrong cookie is not used while dst->obsolete is zero, but\nrt6_get_cookie() may also access per-cpu value when rt->sernum is\nzero. In this case, rt->sernum aliases ioam6_lwt::cache::reset_ts, which\ncan become zero, making this a potential invalid pointer access.\n\nFix this by embedding a full struct rt6_info for the dummy IPv6 route and\npassing its dst member to the dst APIs.","Type":"Description","Title":"ipv6: ioam: fix type confusion of dst_entry"}]}}}