{"id":"CVE-2026-98171","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs\n\nFix several related bounds checking and pointer lifecycle issues in\nreceive_encrypted_standard…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs\n\nFix several related bounds checking and pointer lifecycle issues in\nreceive_encrypted_standard…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= b24df3e30cbf48255db866720fb71f14bf9d2f39 < 72eaef1f37a3b6bec11c342736834dc3707be3e4","Linux >= b24df3e30cbf48255db866720fb71f14bf9d2f39 < 491e33144dee872cffda207f6fcb09260728f803","Linux >= b24df3e30cbf48255db866720fb71f14bf9d2f39 < 8749946579708ea0d339034bb7f423a67dbe89cf","Linux >= b24df3e30cbf48255db866720fb71f14bf9d2f39 < 96c436e4b010711452b2872558938f4ef276492a","Linux >= b24df3e30cbf48255db866720fb71f14bf9d2f39 < 858d5ac22cb889266993e7670f9f0c4f4aeedd78","Linux >= b24df3e30cbf48255db866720fb71f14bf9d2f39 < 05762c5bc1cfdcac36747994fde2c04387a457f1","Linux 4.19"],"published":"2026-10-06","updated":"2026-10-07","sourceUpdated":"2026-10-07T07:17:03.600","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98171","references":[{"url":"https://git.kernel.org/stable/c/05762c5bc1cfdcac36747994fde2c04387a457f1","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/491e33144dee872cffda207f6fcb09260728f803","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/72eaef1f37a3b6bec11c342736834dc3707be3e4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/858d5ac22cb889266993e7670f9f0c4f4aeedd78","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8749946579708ea0d339034bb7f423a67dbe89cf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/96c436e4b010711452b2872558938f4ef276492a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00215,"epssPercentile":0.10812,"ingestedAt":"2026-10-06T08:50:17.457Z","slug":"CVE-2026-98171","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix next_buffer UAF and NextCommand bounds in compound PDUs\n\nFix several related bounds checking and pointer lifecycle issues in\nreceive_encrypted_standard()'s handling of compound encrypted frames:\n\n- Clear next_buffer after assigning it to server->bigbuf. A stale\n  next_buffer pointer can lead to a use-after-free on subsequent\n  error paths.\n- Update pdu_length to the decrypted plaintext size (buf_size). Using\n  the pre-decryption length allows NextCommand to point into stale\n  ciphertext residue.\n- Reject next_cmd values smaller than MID_HEADER_SIZE(server).\n- Fix an integer overflow in the upper bound check by verifying\n  pdu_length - next_cmd < MID_HEADER_SIZE(server), ensuring the\n  trailing slice is large enough for a header.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":217262,"id":"CVE-2026-98171","ts":1791361301861,"field":"cvss","old":null,"new":"8.8"},{"seq":217261,"id":"CVE-2026-98171","ts":1791361301861,"field":"severity","old":"none","new":"high"}]}