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.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-pjp5-fpmr-3349 | GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Mon, 29 Jun 2026 20:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Github
Github github-mcp-server |
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| Vendors & Products |
Github
Github github-mcp-server |
Sat, 27 Jun 2026 03:30:00 +0000
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|---|---|---|
| Metrics |
ssvc
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Fri, 26 Jun 2026 16:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion | |
| Weaknesses | CWE-284 | |
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-06-27T02:43:34.588Z
Reserved: 2026-05-21T16:18:10.619Z
Link: CVE-2026-48529
Updated: 2026-06-27T02:43:21.930Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-06-29T20:06:16Z
Weaknesses
Github GHSA