CVE-2026-48529

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Source
https://cve.org/CVERecord?id=CVE-2026-48529
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48529.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-48529
Aliases
Published
2026-06-26T16:33:32.688Z
Modified
2026-07-15T01:49:12.264325433Z
Severity
  • 6.0 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L CVSS Calculator
Summary
GitHub MCP Server: Lockdown mode singleton in HTTP server causes cross-user GraphQL client confusion
Details

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.

Database specific 
{
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48529.json",
    "cwe_ids": [
        "CWE-284"
    ]
}
References

Affected packages

Git / github.com/github/github-mcp-server

Affected ranges

Type
GIT
Repo
https://github.com/github/github-mcp-server
Events
Introduced
6a57e75d729f9767827bc4f96e80ff9bd8538a46
Fixed
b5397f6e3305531a1c534b90b2d347a70fa84da9
Database specific 
{
    "extracted_events": [
        {
            "introduced": "0.22.0"
        },
        {
            "fixed": "1.1.2"
        }
    ],
    "source": "AFFECTED_FIELD"
}

Affected versions

v0.*
v0.22.0
v0.23.0
v0.24.0
v0.24.1
v0.25.0
v0.26.0
v0.26.1
v0.26.2
v0.26.3
v0.27.0
v0.28.0
v0.28.1
v0.29.0
v0.30.0
v0.30.1
v0.30.2
v0.30.3
v0.31.0
v0.32.0
v0.33.0
v0.33.1
v1.*
v1.0.0
v1.0.1
v1.0.2
v1.0.3
v1.0.4
v1.0.5
v1.1.0
v1.1.1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48529.json"