{"id":"CVE-2026-90191","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nmailbox: riscv-sbi-mpxy: validate RPMI notification lengths\n\nThe SBI return value controls how many bytes are copied from shared\nmemory into the RPMI notification buffe…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nmailbox: riscv-sbi-mpxy: validate RPMI notification lengths\n\nThe SBI return value controls how many bytes are copied from shared\nmemory into the RPMI notification buffe…","severity":"high","cvss":8.4,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= bf3022a4eb119c6b4e3424d6b19d8bfdfbc9bb57 < cbc24bce70dfd91c7b2f53b4fa896e9a4b6d6a6b","Linux >= bf3022a4eb119c6b4e3424d6b19d8bfdfbc9bb57 < c7bc5e7677bcda7a446d63b989cfaa3fe91d6b76","Linux >= bf3022a4eb119c6b4e3424d6b19d8bfdfbc9bb57 < 11d5af151bcbe78f5a579e0faecd3be9cea0399a","Linux 6.18"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:17:45.823","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90191","references":[{"url":"https://git.kernel.org/stable/c/11d5af151bcbe78f5a579e0faecd3be9cea0399a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c7bc5e7677bcda7a446d63b989cfaa3fe91d6b76","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cbc24bce70dfd91c7b2f53b4fa896e9a4b6d6a6b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.0018,"epssPercentile":0.07884,"ingestedAt":"2026-09-17T16:21:47.863Z","slug":"CVE-2026-90191","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nmailbox: riscv-sbi-mpxy: validate RPMI notification lengths\n\nThe SBI return value controls how many bytes are copied from shared\nmemory into the RPMI notification buffer. It is not validated against\nthe negotiated shared-memory size before that copy. The event walker\nalso uses a reversed loop condition and can inspect a short event record.\n\nValidate the complete notification length before copying it, iterate only\nwhile a full event header remains, and stop when a declared event payload\nextends beyond the copied notification data.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":46,"depthScoreParts":{"impact":46.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":207169,"id":"CVE-2026-90191","ts":1789757338210,"field":"cvss","old":null,"new":"8.4"},{"seq":207168,"id":"CVE-2026-90191","ts":1789757338210,"field":"severity","old":"none","new":"high"}]}