{"id":"CVE-2026-98596","title":"ipv6: Fix dst leak for uncached routes.","summary":"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),…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < 5045aa25f3790dcdb158a58ac60ccf8da42959aa","Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < ed902d5546fb9c142b3216d8eec914fa1bc0aa80","Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < f9722746df13a8a29103c847ef56b02c11ce0963","Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < be31fe6333f534155e6b408f1ef6d77974bb41aa","Linux 6.11"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:19:09.189Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98596","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"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.246Z","slug":"CVE-2026-98596","body":"## Overview\n\nIn 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.\n\n## Affected\n\n- `Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < 5045aa25f3790dcdb158a58ac60ccf8da42959aa`\n- `Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < ed902d5546fb9c142b3216d8eec914fa1bc0aa80`\n- `Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < f9722746df13a8a29103c847ef56b02c11ce0963`\n- `Linux >= 98aa546af5e4f180439c82da403cc77926d3953b < be31fe6333f534155e6b408f1ef6d77974bb41aa`\n- `Linux 6.11`\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":[]}