@sylphx/pdf-reader-mcp: HTTP transport accepts unauthenticated requests despite a configured MCP_API_KEY
CVE-2026-62264
Impact When @sylphx/pdf-reader-mcp is run as an HTTP server (MCPTRANSPORT=http), it reads the MCPAPIKEY environment variable and logs API key authentication enabled (X-API-Key header) at startup, but it never validated the X-API-Key header on incoming requests. The key was read into a variable and never enforced on the request path. As a result, the /mcp endpoint accepted unauthenticated requests. Combined with the default bind address of 0.0.0.0 (all interfaces), any client able to reach the port could invoke every PDF tool and read the contents of any PDF the server process could open anywhere on the host. URL-based sources also enable limited SSRF (private/loopback addresses are blocked by default unless --allow-private-ips is set). The misleading startup log made the exposure silent: an operator who set MCPAPIKEY reasonably believed the server was protected when it was not. This affects only the opt-in HTTP transport; the default stdio transport is unaffected. Patches Fixed in @sylphx/pdf-reader-mcp@3.0.1. The fix enforces the X-API-Key header with a constant-time comparison (rejecting missing/mismatched keys with HTTP 401), changes the default bind host to 127.0.0.1…
Part of the AI stack
This affects Model Context Protocol, in MCP & tool servers.
Assessment
- CVSS
- 7.5 (v3.1)
- Severity
- High
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 29 October 2026
- Last updated
- 29 October 2026
- Affected
- npm · @sylphx/pdf-reader-mcp
- Weakness
- CWE-200, CWE-287, CWE-306
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
At the source
References
- https://github.com/SylphxAI/pdf-reader-mcp/security/advisories/GHSA-q344-5v34-gm84
- https://github.com/SylphxAI/anymd/pull/332
- https://github.com/SylphxAI/anymd/commit/4c35f72862d729301e3912ab8c8317d2828cf4c2
- https://github.com/SylphxAI/anymd/releases/tag/v3.0.1
- https://github.com/advisories/GHSA-q344-5v34-gm84
Query this programmatically
Agents can read this through the MCP endpoint, or over HTTP:
curl https://cve.zerocrew.in/api/cve/CVE-2026-62264