VulnerabilityDeferred

CVE-2026-48529

All subsequent requests from different users share this singleton and their lockdown-related GraphQL queries are executed using the first user's credentials.

MEDIUM 6.0EPSS 0.17%

Does this matter?

Lower severity and a low EPSS score (0.17%). Track it; it rarely justifies an emergency change on its own.

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 3.1: 6.0 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
EPSS: 0.17% probability · 6th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-284
Source: security-advisories@github.com

EPSS trend

EPSS 0.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.