{"id":"CVE-2026-80843","title":"xfrm: fix xfrm_state_construct() auth-trunc leak","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix xfrm_state_construct() auth-trunc leak\n\nattach_auth_trunc() can allocate x->aalg while leaving\nx->props.aalgo at zero when the selected auth algorithm has no\n…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < 958ae9f261319e1cdc44879886bcda2263258cca","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < fb7f3e74789a3c89647f4eb768f6dfaf4a751e72","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < ba0c110c205855b3f1e3130d8c0fdb484d704c8c","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < c8837bbe792257af547fd1c0252553ce13148795","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < 71d42da01740ec6557837bebec0bc48cfc3b4c39","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < cf67361e78dca488d6e4df8396a53e6745a3a80e","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < 37426395cb90ef217beec8407a14bd82153793d3","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < be19d20e53a239572bb2a28efcc1cd2b069b1ef9","Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < c12cbf56320fb633484ee0ca1fb7d68d6b64b213","Linux 2.6.33"],"published":"2026-09-04","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:44:36.352Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-80843","references":[{"url":"https://git.kernel.org/stable/c/958ae9f261319e1cdc44879886bcda2263258cca"},{"url":"https://git.kernel.org/stable/c/fb7f3e74789a3c89647f4eb768f6dfaf4a751e72"},{"url":"https://git.kernel.org/stable/c/ba0c110c205855b3f1e3130d8c0fdb484d704c8c"},{"url":"https://git.kernel.org/stable/c/c8837bbe792257af547fd1c0252553ce13148795"},{"url":"https://git.kernel.org/stable/c/71d42da01740ec6557837bebec0bc48cfc3b4c39"},{"url":"https://git.kernel.org/stable/c/cf67361e78dca488d6e4df8396a53e6745a3a80e"},{"url":"https://git.kernel.org/stable/c/37426395cb90ef217beec8407a14bd82153793d3"},{"url":"https://git.kernel.org/stable/c/be19d20e53a239572bb2a28efcc1cd2b069b1ef9"},{"url":"https://git.kernel.org/stable/c/c12cbf56320fb633484ee0ca1fb7d68d6b64b213"}],"tags":["cve.org"],"epss":0.00195,"epssPercentile":0.08585,"ingestedAt":"2026-10-19T09:16:01.497Z","slug":"CVE-2026-80843","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: fix xfrm_state_construct() auth-trunc leak\n\nattach_auth_trunc() can allocate x->aalg while leaving\nx->props.aalgo at zero when the selected auth algorithm has no\nsadb_alg_id. One real case is cmac(aes).\n\nxfrm_state_construct() then treats !x->props.aalgo as \"no auth\nalgorithm attached yet\" and calls attach_auth(). That overwrites\nx->aalg and loses the first allocation. Any later failure or teardown\nonly frees the replacement pointer.\n\nCheck whether x->aalg is already attached instead of inferring that\nstate from x->props.aalgo.\n\n## Affected\n\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < 958ae9f261319e1cdc44879886bcda2263258cca`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < fb7f3e74789a3c89647f4eb768f6dfaf4a751e72`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < ba0c110c205855b3f1e3130d8c0fdb484d704c8c`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < c8837bbe792257af547fd1c0252553ce13148795`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < 71d42da01740ec6557837bebec0bc48cfc3b4c39`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < cf67361e78dca488d6e4df8396a53e6745a3a80e`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < 37426395cb90ef217beec8407a14bd82153793d3`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < be19d20e53a239572bb2a28efcc1cd2b069b1ef9`\n- `Linux >= 4447bb33f09444920a8f1d89e1540137429351b6 < c12cbf56320fb633484ee0ca1fb7d68d6b64b213`\n- `Linux 2.6.33`\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":[]}