{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48529","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-21T16:18:10.619Z","datePublished":"2026-06-26T16:33:32.688Z","dateUpdated":"2026-06-27T02:43:34.588Z"},"containers":{"cna":{"title":"GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion","problemTypes":[{"descriptions":[{"cweId":"CWE-284","lang":"en","description":"CWE-284: Improper Access Control","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":6,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L","version":"3.1"}}],"references":[{"name":"https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349","tags":["x_refsource_CONFIRM"],"url":"https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349"}],"affected":[{"vendor":"github","product":"github-mcp-server","versions":[{"version":">= 0.22.0, < 1.1.2","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-06-26T16:33:32.688Z"},"descriptions":[{"lang":"en","value":"GitHub MCP Server is GitHub's official MCP Server. From 0.22.0 until 1.1.2, when running in HTTP mode with --lockdown-mode enabled, the RepoAccessCache is implemented as a process-global singleton initialized with the first authenticated user's GraphQL client. All subsequent requests from different users share this singleton and their lockdown-related GraphQL queries are executed using the first user's credentials. The singleton is never updated to reflect later users' tokens. This vulnerability is fixed in 1.1.2."}],"source":{"advisory":"GHSA-pjp5-fpmr-3349","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-27T02:42:44.775898Z","id":"CVE-2026-48529","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-06-27T02:43:34.588Z"}}]}}