{"id":"CVE-2026-68426","aliases":[],"url":"https://o3.security/vulnerability/CVE-2026-68426","summary":"xfrm: fix stale skb->prev after async crypto steals a GSO segment","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix stale skb->prev after async crypto steals a GSO segment\n\nskb_gso_segment() leaves the segment list head with ->prev pointing at\nthe last segment, an invariant validate_xmit_skb_list() relies on when\nit sets its tail pointer (tail = skb->prev).\n\nWhen validate_xmit_xfrm() walks a GSO list and some segments are stolen\nby async crypto (->xmit() returns -EINPROGRESS), those segments are\nunlinked from the list but the head ->prev is never updated.  If the\nlast segment is the one stolen, the returned head still has ->prev\npointing at it, even though it is now owned by the crypto engine and may\nbe freed.  validate_xmit_skb_list() later does tail->next = skb, writing\nthrough that stale pointer -- a use-after-free.\n\nRepoint skb->prev at the last retained segment before returning.","published":"2026-08-10T12:04:46.945Z","modified":"2026-08-14T04:03:38.863815377Z","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":"6.18.42"}],"fix":null,"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/33e1b0d25ca0d2818c635ff80e6aa0d295e08a98"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3f4c3919baf0944ad96580467c302bc6c7758b00"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bbca7cc3b2b4b10afbfee99b81d9ee78f5423046"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68426.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-68426"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-14T04:03:38.863815377Z"}}