{"affected":[{"defaultStatus":"unaffected","product":"siyuan","source":"CNA: VulnCheck","vendor":"siyuan-note","versions":[{"lessThan":"3.8.9","status":"affected","version":"0","versionType":"semver"},{"status":"unaffected","version":"3.8.9","versionType":"semver"}]}],"cveId":"CVE-2026-123492","cwes":["CWE-476"],"description":"SiYuan before 3.8.9 contains a nil pointer dereference vulnerability in privateCacheMiddleware that allows authenticated attackers to crash the kernel by reading nonexistent MCP resources. Attackers with a valid API token can send a resources/read request in an initialized MCP session, causing a panic that terminates the kernel process and interrupts service.","epss":{"date":"2026-11-09","percentile":0.18877,"score":0.00266},"exploits":[],"kev":null,"metrics":[{"score":6.9,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},{"score":4.9,"severity":"medium","source":"CNA: VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},{"score":6.9,"severity":"medium","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","version":"4.0"},{"score":4.9,"severity":"medium","source":"NVD: disclosure@vulncheck.com","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1794266235640,"publishedAt":1793977252853,"references":[{"source":"CNA: VulnCheck","tags":["vendor-advisory"],"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2x3p-x74g-442x"},{"source":"CNA: VulnCheck","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.9-nil-pointer-dereference-dos-via-mcp-resources-read"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2x3p-x74g-442x"},{"source":"disclosure@vulncheck.com","tags":[],"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.9-nil-pointer-dereference-dos-via-mcp-resources-read"}],"remediation":[],"revision":"79ec7f458729e93c2c5ec0f17014217a22258d14daa53872197e5b0a58f699b1","sources":[{"modifiedAt":1794264347227,"name":"CNA: VulnCheck","retrievedAt":1794265747659,"url":"https://www.cve.org/CVERecord?id=CVE-2026-123492"},{"modifiedAt":1794266235640,"name":"NVD","retrievedAt":1794269915597,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123492"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1794265766574,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-123492"}],"ssvc":{"assessedAt":1794263676965,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read","updatedAt":1794269915597}