{"cve":"CVE-2026-48529","nvd":{"published":"2026-06-26T17:16:33.820","modified":"2026-10-25T17:10:00.197","status":"Deferred","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L","score":6.0},"cwes":["CWE-284"],"references":["https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349","https://github.com/github/github-mcp-server/security/advisories/GHSA-pjp5-fpmr-3349"],"products":[],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-48529","score":0.00205,"percentile":0.10424,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-pjp5-fpmr-3349","url":"https://osv.dev/vulnerability/GHSA-pjp5-fpmr-3349","summary":"GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion","modified":"2026-07-07T16:11:35.157935325Z","packages":[{"ecosystem":"Go","name":"github.com/github/github-mcp-server","purl":"pkg:golang/github.com/github/github-mcp-server","ranges":[">=0.22.0 <1.1.2"],"fixed":["1.1.2"]}]},{"id":"GO-2026-5779","url":"https://osv.dev/vulnerability/GO-2026-5779","summary":"GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion in github.com/github/github-mcp-server","modified":"2026-07-07T16:00:20.661126655Z","packages":[{"ecosystem":"Go","name":"github.com/github/github-mcp-server","purl":"pkg:golang/github.com/github/github-mcp-server","ranges":[">=0.22.0 <1.1.2"],"fixed":["1.1.2"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}