{"id":"CVE-2026-80838","title":"vxlan: keep the last remote linked during FDB flush","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: keep the last remote linked during FDB flush\n\nA non-nexthop FDB entry is expected to have at least one remote while it\nremains reachable through the FDB hash tab…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < 2a7c2f00843225d5f037676bca649321f3d024c7","Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < a8820c8a7718327e96849782033e7c85a0f6bcfe","Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < 8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c","Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < 4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab","Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < d5d4a7b538b52db63927773a8905fcd9f78a42e2","Linux 6.7"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:30.457Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80838","references":[{"url":"https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7"},{"url":"https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe"},{"url":"https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c"},{"url":"https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab"},{"url":"https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2"}],"tags":["cve.org"],"epss":0.00168,"epssPercentile":0.05686,"ingestedAt":"2026-10-19T09:16:01.499Z","slug":"CVE-2026-80838","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: keep the last remote linked during FDB flush\n\nA non-nexthop FDB entry is expected to have at least one remote while it\nremains reachable through the FDB hash table. A filtered bulk flush\nviolates this invariant when every remote matches: It unlinks the last\nremote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush()\nto destroy the parent FDB entry.\n\nAn RCU reader can find the parent during this interval.\nfirst_remote_rcu() then applies list_entry_rcu() to the empty list head,\nproducing an invalid remote pointer that the receive learning path can\nread from and write to.\n\nWhen a matching remote is the sole remaining remote, leave it linked and\nask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps\nthe remote attached while sending the deletion notification and removing\nthe parent from the lookup structures.\n\n## Affected\n\n- `Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < 2a7c2f00843225d5f037676bca649321f3d024c7`\n- `Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < a8820c8a7718327e96849782033e7c85a0f6bcfe`\n- `Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < 8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c`\n- `Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < 4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab`\n- `Linux >= c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f < d5d4a7b538b52db63927773a8905fcd9f78a42e2`\n- `Linux 6.7`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}