{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-123492","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","state":"PUBLISHED","assignerShortName":"VulnCheck","dateReserved":"2026-11-06T00:44:37.659Z","datePublished":"2026-11-06T15:00:52.853Z","dateUpdated":"2026-11-06T15:00:52.853Z"},"containers":{"cna":{"providerMetadata":{"orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","shortName":"VulnCheck","dateUpdated":"2026-11-06T15:00:52.853Z"},"datePublic":"2026-10-22T00:00:00.000Z","title":"SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read","descriptions":[{"lang":"en","value":"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."}],"problemTypes":[{"descriptions":[{"lang":"en","description":"NULL Pointer Dereference","cweId":"CWE-476","type":"CWE"}]}],"affected":[{"vendor":"siyuan-note","product":"siyuan","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","versionType":"semver","lessThan":"3.8.9"},{"version":"3.8.9","status":"unaffected","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*","versionEndExcluding":"3.8.9"}]}]}],"metrics":[{"format":"CVSS","cvssV4_0":{"version":"4.0","vectorString":"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","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM"}},{"format":"CVSS","cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":4.9,"baseSeverity":"MEDIUM"}}],"references":[{"url":"https://github.com/siyuan-note/siyuan/security/advisories/GHSA-2x3p-x74g-442x","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-2x3p-x74g-442x)"},{"name":"VulnCheck Advisory: SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read","tags":["third-party-advisory"],"url":"https://www.vulncheck.com/advisories/siyuan-before-3.8.9-nil-pointer-dereference-dos-via-mcp-resources-read"}],"credits":[{"lang":"en","value":"xy3xy3","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}