MCP Registry's GitHub OIDC tokens are replayable across registry deployments due to shared audience

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

2.1 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N · score source

EPSS

• CVE-2026-44428: 0.22% estimated exploitation activity in the next 30 days; percentile 12.45 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

[SECURITY] registry001 Vulnerability Report While analyzing the code logic, an area that may lead to unintended behavior under specific conditions was discovered. Overview - Verified Version: c5c4b9e8890dd5754bee889b2f1417f4fe3b5ce5 - Vulnerability Type: Authentication bypass via cross-registry OIDC token replay - Affected Location: cmd/publisher/commands/login.go:67-105,130-135,199-224; cmd/publisher/auth/github-oidc.go:24-38,58-75,108-165; internal/api/handlers/v0/auth/githuboidc.go:75-135,229-277,280-296 - Trigger Scenario: a workflow invokes mcp-publisher login github-oidc --registry <other-registry (or equivalent publish flow) and the publisher still requests a GitHub Actions ID token with the shared audience mcp-registry; any other registry deployment running this code can replay that token to its own /v0/auth/github-oidc endpoint and mint a publish-capable registry JWT for the same GitHub owner namespace. Root Cause The client-side and server-side GitHub OIDC flow is bound…

Published by the source

8 May 2026, 17:06 UTC

Last modified by the source

1 Jun 2026, 08:45 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-95c3-6vvw-4mrq

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# Patch Next advisory brief: CVE-2026-44428

Advisory: MCP Registry's GitHub OIDC tokens are replayable across registry deployments due to shared audience
IDs: CVE-2026-44428, GHSA-95c3-6vvw-4mrq
Record: https://patchnext.com/advisories/cve-2026-44428 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/modelcontextprotocol/registry 1.7.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/modelcontextprotocol/registry: affected < 1.7.6; fixed in 1.7.6

## Suggested inspection (read-only)
- Go github.com/modelcontextprotocol/registry: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/modelcontextprotocol/registry.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-95c3-6vvw-4mrq (GitHub-reviewed advisory GHSA-95c3-6vvw-4mrq lists affected ranges: Go github.com/modelcontextprotocol/registry >=0 <1.7.6)

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