Vulnerability · Published May 26, 2026 · Assigned by GitHub_M
CVE-2026-44895GitLab MCP Server: SSE transport has no authentication and wildcard CORS, exposing all GitLab tools
Critical 9.2
In plain English
A critical-severity missing authentication in mcp-gitlab-server from yoda-digital. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @yoda.digital/gitlab-mcp-server | 0.6.0 | GHSA-8jr5-6gvj-rfpf |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| yoda-digital | mcp-gitlab-server | < 0.6.0 |
Weakness: CWE-306, CWE-942 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N