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Critical · 9.2 CVE-2026-44895 EUVD-2026-32003GHSA-8jr5-6gvj-rfpf

GitLab MCP Server: SSE transport has no authentication and wildcard CORS, exposing all GitLab tools

Published May 26, 2026 · Updated May 27, 2026 · Assigned by GitHub_M

Description

GitLab MCP Server lets an AI agent talk directly to GitLab. Prior to 0.6.0, the HTTP transport in src/transport.ts ships with no authentication layer at all and a wildcard Access-Control-Allow-Origin: * on every response. The structural defect is that the SSE server stands up a stateful, mutation-capable RPC endpoint that is backed by the operator's GITLAB_PERSONAL_ACCESS_TOKEN without any inbound credential check, then advertises itself to every cross-origin browser context via the wildcard CORS header. The httpServer.listen(port) call at line 97 also passes no host argument, so the bind defaults to 0.0.0.0 and exposes the auth-less surface on every interface. This vulnerability is fixed in 0.6.0.

Affected products

VendorProductAffectedFixed
yoda-digital mcp-gitlab-server < 0.6.0 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm @yoda.digital/gitlab-mcp-server < 0.6.0 0.6.0 GHSA-8jr5-6gvj-rfpf

References