{"id":"CVE-2026-85580","title":"SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems","summary":"SiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-va…","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-22"],"published":"2026-09-04","updated":"2026-09-08","sourceUpdated":"2026-09-08T20:05:53.177","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-85580","references":[{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.2-path-guard-bypass-via-case-mismatch","label":"disclosure@vulncheck.com"},{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-mmgw-3mx9-cfwp","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"tags":["nvd"],"epss":0.00526,"epssPercentile":0.43341,"ingestedAt":"2026-09-08T20:10:03.164Z","slug":"CVE-2026-85580","body":"## Overview\n\nSiYuan versions before v3.8.2 contain a path guard bypass vulnerability in the MCP file-access handler that uses case-sensitive matching on Linux filesystems. Attackers can read the protected publishAccess.json file by requesting case-variant paths like PublishAccess.json to disclose sensitive publish-access configuration and metadata.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}