{"id":"CVE-2026-80838","state":"PUBLISHED","title":"vxlan: keep the last remote linked during FDB flush","description":"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 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.","publishedAt":"2026-09-04T15:54:48.371Z","updatedAt":"2026-10-19T08:44:30.457Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"2a7c2f00843225d5f037676bca649321f3d024c7","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"a8820c8a7718327e96849782033e7c85a0f6bcfe","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"d5d4a7b538b52db63927773a8905fcd9f78a42e2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.12.108","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.49","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]}],"references":["https://git.kernel.org/stable/c/2a7c2f00843225d5f037676bca649321f3d024c7","https://git.kernel.org/stable/c/a8820c8a7718327e96849782033e7c85a0f6bcfe","https://git.kernel.org/stable/c/8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c","https://git.kernel.org/stable/c/4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab","https://git.kernel.org/stable/c/d5d4a7b538b52db63927773a8905fcd9f78a42e2"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80838.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80838","state":"PUBLISHED","datePublished":"2026-09-04T15:54:48.371Z","dateUpdated":"2026-10-19T08:44:30.457Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.796Z"},"containers":{"cna":{"title":"vxlan: keep the last remote linked during FDB flush","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"2a7c2f00843225d5f037676bca649321f3d024c7","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"a8820c8a7718327e96849782033e7c85a0f6bcfe","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"8ba68fd6cdd1e3c92b92f25c7e48bf7bd51a183c","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"4bbc76ee1b21d3bd045d6d819b2bacd30a6372ab","versionType":"git"},{"version":"c499fccb71cb85902b5c5b9ce9c9ae6683e54a8f","status":"affected","lessThan":"d5d4a7b538b52db63927773a8905fcd9f78a42e2","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.7","versionType":"semver"},{"version":"6.12.108","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.49","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/vxlan/vxlan_core.c"]}],"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"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:44:30.457Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.12.108"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"6.18.49"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.1.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.7","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}