{"id":"CVE-2026-72429","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-72429","summary":"ipv6: ioam: fix type confusion of dst_entry","details":"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.","published":"2026-08-15T05:56:45.530Z","modified":"2026-08-18T03:56:55.789337130Z","cvss":{"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"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"Linux","name":"Kernel","fixedVersion":"6.18.40"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/5a3b2ee1e96d0580a8ed8deda6dfa430604f9ab0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9ed19e11d2146076d117d51a940643990118449b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ea24f911ead85ba3d570a31e37c52b6c949f6928"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72429.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72429"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-18T03:56:55.789337130Z"}}