{"id":"CVE-2026-98596","state":"PUBLISHED","title":"ipv6: Fix dst leak for uncached routes.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: Fix dst leak for uncached routes.\n\nip6_route_output_flags(), ip6_rt_put_flags(), and ip6_dst_check()\ndetect an uncached route by list_empty(&rt->dst.rt_uncached),\nwhich replaced the static DST_NOCACHE flag check in commit\na4c2fd7f7891 (\"net: remove DST_NOCACHE flag\").\n\nWhen a device is unregistered, rt6_uncached_list_flush_dev()\nunlinks uncached routes tied to the device from rt6_uncached_list.\n\nPreviously, they were moved to another list with list_move()\n(__list_del_entry() + list_add()), and since commit 98aa546af5e4\n(\"inet: remove (struct uncached_list)->quarantine\"), the routes\nare just unlinked with list_del_init().\n\nIf list_del_init() runs concurrently, list_empty() evaluates to\ntrue; ip6_route_output_flags() calls dst_hold_safe() incorrectly\nand ip6_rt_put_flags() skips ip6_rt_put(), leaking dst, and thus\ndev tied via rt->from as well.\n\nThe same race is partially fixed by commit 9a6f0c4d5796 (\"dst:\nfix races in rt6_uncached_list_del() and rt_del_uncached_list()\").\n\nLet's check rt6->dst.rt_uncached_list instead.\n\nNote that IPv4 does not have the same issue.","publishedAt":"2026-10-18T15:19:09.189Z","updatedAt":"2026-10-19T09:22:21.750Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"5045aa25f3790dcdb158a58ac60ccf8da42959aa","versionType":"git"},{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"ed902d5546fb9c142b3216d8eec914fa1bc0aa80","versionType":"git"},{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"f9722746df13a8a29103c847ef56b02c11ce0963","versionType":"git"},{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"be31fe6333f534155e6b408f1ef6d77974bb41aa","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/ip6_route.h","net/ipv6/route.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","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":["include/net/ip6_route.h","net/ipv6/route.c"]}],"references":["https://git.kernel.org/stable/c/5045aa25f3790dcdb158a58ac60ccf8da42959aa","https://git.kernel.org/stable/c/ed902d5546fb9c142b3216d8eec914fa1bc0aa80","https://git.kernel.org/stable/c/f9722746df13a8a29103c847ef56b02c11ce0963","https://git.kernel.org/stable/c/be31fe6333f534155e6b408f1ef6d77974bb41aa"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/98xxx/CVE-2026-98596.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-98596","state":"PUBLISHED","datePublished":"2026-10-18T15:19:09.189Z","dateUpdated":"2026-10-19T09:22:21.750Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.359Z"},"containers":{"cna":{"title":"ipv6: Fix dst leak for uncached routes.","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: Fix dst leak for uncached routes.\n\nip6_route_output_flags(), ip6_rt_put_flags(), and ip6_dst_check()\ndetect an uncached route by list_empty(&rt->dst.rt_uncached),\nwhich replaced the static DST_NOCACHE flag check in commit\na4c2fd7f7891 (\"net: remove DST_NOCACHE flag\").\n\nWhen a device is unregistered, rt6_uncached_list_flush_dev()\nunlinks uncached routes tied to the device from rt6_uncached_list.\n\nPreviously, they were moved to another list with list_move()\n(__list_del_entry() + list_add()), and since commit 98aa546af5e4\n(\"inet: remove (struct uncached_list)->quarantine\"), the routes\nare just unlinked with list_del_init().\n\nIf list_del_init() runs concurrently, list_empty() evaluates to\ntrue; ip6_route_output_flags() calls dst_hold_safe() incorrectly\nand ip6_rt_put_flags() skips ip6_rt_put(), leaking dst, and thus\ndev tied via rt->from as well.\n\nThe same race is partially fixed by commit 9a6f0c4d5796 (\"dst:\nfix races in rt6_uncached_list_del() and rt_del_uncached_list()\").\n\nLet's check rt6->dst.rt_uncached_list instead.\n\nNote that IPv4 does not have the same issue."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"5045aa25f3790dcdb158a58ac60ccf8da42959aa","versionType":"git"},{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"ed902d5546fb9c142b3216d8eec914fa1bc0aa80","versionType":"git"},{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"f9722746df13a8a29103c847ef56b02c11ce0963","versionType":"git"},{"version":"98aa546af5e4f180439c82da403cc77926d3953b","status":"affected","lessThan":"be31fe6333f534155e6b408f1ef6d77974bb41aa","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["include/net/ip6_route.h","net/ipv6/route.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.55","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.9","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":["include/net/ip6_route.h","net/ipv6/route.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/5045aa25f3790dcdb158a58ac60ccf8da42959aa"},{"url":"https://git.kernel.org/stable/c/ed902d5546fb9c142b3216d8eec914fa1bc0aa80"},{"url":"https://git.kernel.org/stable/c/f9722746df13a8a29103c847ef56b02c11ce0963"},{"url":"https://git.kernel.org/stable/c/be31fe6333f534155e6b408f1ef6d77974bb41aa"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T09:22:21.750Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.18.55"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.2.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}