{"id":"CVE-2026-43091","title":"xfrm: Wait for RCU readers during policy netns exit","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Wait for RCU readers during policy netns exit\n\nxfrm_policy_fini() frees the policy_bydst hash tables after flushing the\npolicy work items and deleting all policie…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < b66920a3348c0f63ba18365248fa21fbf0b3a937","Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 438b1f668ad58f46ce699bb48e4698a7839e3f9e","Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 3733fce2871c9bca9dd18a1a23b1432ea215a094","Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 33a3149dd81a1e2f52b80ee1e0fc380b39f3d028","Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 069daad4f2ae9c5c108131995529d5f02392c446","Linux 4.9"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:14:31.928454Z"},"published":"2026-05-06","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:32.241Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43091","references":[{"url":"https://git.kernel.org/stable/c/b66920a3348c0f63ba18365248fa21fbf0b3a937"},{"url":"https://git.kernel.org/stable/c/438b1f668ad58f46ce699bb48e4698a7839e3f9e"},{"url":"https://git.kernel.org/stable/c/3733fce2871c9bca9dd18a1a23b1432ea215a094"},{"url":"https://git.kernel.org/stable/c/33a3149dd81a1e2f52b80ee1e0fc380b39f3d028"},{"url":"https://git.kernel.org/stable/c/069daad4f2ae9c5c108131995529d5f02392c446"}],"tags":["cve.org"],"epss":0.00175,"epssPercentile":0.06558,"ingestedAt":"2026-10-16T17:24:46.681Z","slug":"CVE-2026-43091","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: Wait for RCU readers during policy netns exit\n\nxfrm_policy_fini() frees the policy_bydst hash tables after flushing the\npolicy work items and deleting all policies, but it does not wait for\nconcurrent RCU readers to leave their read-side critical sections first.\n\nThe policy_bydst tables are published via rcu_assign_pointer() and are\nlooked up through rcu_dereference_check(), so netns teardown must also\nwait for an RCU grace period before freeing the table memory.\n\nFix this by adding synchronize_rcu() before freeing the policy hash tables.\n\n## Affected\n\n- `Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < b66920a3348c0f63ba18365248fa21fbf0b3a937`\n- `Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 438b1f668ad58f46ce699bb48e4698a7839e3f9e`\n- `Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 3733fce2871c9bca9dd18a1a23b1432ea215a094`\n- `Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 33a3149dd81a1e2f52b80ee1e0fc380b39f3d028`\n- `Linux >= e1e551bc56302b80ff930c966f9985095fb1b70d < 069daad4f2ae9c5c108131995529d5f02392c446`\n- `Linux 4.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}