{"id":"CVE-2026-68426","title":"xfrm: fix stale skb->prev after async crypto steals a GSO segment","summary":"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…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= f53c723902d1ac5f0b0a11d7c9dcbff748dde74e < 33e1b0d25ca0d2818c635ff80e6aa0d295e08a98","Linux >= f53c723902d1ac5f0b0a11d7c9dcbff748dde74e < bbca7cc3b2b4b10afbfee99b81d9ee78f5423046","Linux >= f53c723902d1ac5f0b0a11d7c9dcbff748dde74e < 3f4c3919baf0944ad96580467c302bc6c7758b00","Linux 4.16"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:48:46.371818Z"},"published":"2026-08-10","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:53:13.083Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-68426","references":[{"url":"https://git.kernel.org/stable/c/33e1b0d25ca0d2818c635ff80e6aa0d295e08a98"},{"url":"https://git.kernel.org/stable/c/bbca7cc3b2b4b10afbfee99b81d9ee78f5423046"},{"url":"https://git.kernel.org/stable/c/3f4c3919baf0944ad96580467c302bc6c7758b00"}],"tags":["cve.org"],"epss":0.00362,"epssPercentile":0.28493,"ingestedAt":"2026-10-16T17:24:46.868Z","slug":"CVE-2026-68426","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= f53c723902d1ac5f0b0a11d7c9dcbff748dde74e < 33e1b0d25ca0d2818c635ff80e6aa0d295e08a98`\n- `Linux >= f53c723902d1ac5f0b0a11d7c9dcbff748dde74e < bbca7cc3b2b4b10afbfee99b81d9ee78f5423046`\n- `Linux >= f53c723902d1ac5f0b0a11d7c9dcbff748dde74e < 3f4c3919baf0944ad96580467c302bc6c7758b00`\n- `Linux 4.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}