PDF Reader MCP server lets anyone on the network read your PDFs
If you run this PDF tool in HTTP mode, anyone who can reach its network port can use it without a password, and read PDF files on the machine. Setting an API key did not actually protect it.
| Severity | HighCVSS 7.5 of 10 |
|---|---|
| Being exploited? | UnclearNo reports either way yet |
| Fix available? | Yes@sylphx/pdf-reader-mcp 3.0.1 (enforces X-API-Key with constant-time comparison, defaults to 127.0.0.1, warns when binding non-loopback without a key) · since 29 Oct 2026 |
| How sure is this? | Official, 2 sourcesBacked by an official source |
How the attack works simplified
- 1Remote clientReaches the open port on the network
- 2HTTP /mcp endpointKey header is logged but never checked
- 3PDF tools runAny tool is callable without auth
- 4Local PDFs readAny file the process can open
- ResultAttacker reads PDFs without credentials
What happened
In @sylphx/pdf-reader-mcp versions 2.2.0 to before 3.0.1, the HTTP transport's /mcp endpoint never checks the X-API-Key header, despite logging that API key authentication is enabled. It also binds to 0.0.0.0 by default, exposing it on all network interfaces; URL sources allow limited SSRF.
Are you affected?
You are affected if you run @sylphx/pdf-reader-mcp 2.2.0 through 3.0.0 with MCP_TRANSPORT=http, especially with the default 0.0.0.0 bind address and reachable from a network you do not fully trust. The default stdio transport is not affected.
| Package / product | Affected versions | Fixed in |
|---|---|---|
| @sylphx/pdf-reader-mcp · npm | >= 2.2.0, < 3.0.1 | 3.0.1 |
What to do
- Update @sylphx/pdf-reader-mcp to 3.0.1 or later
- If you cannot upgrade yet, bind to loopback only with MCP_HTTP_HOST=127.0.0.1
- Or place an authenticating reverse proxy in front, or switch to the stdio transport
- Restrict readable folders with --allow-dir or MCP_PDF_ALLOWED_DIRS
Timeline
- 29 Oct 2026, 16:34 UTCPublicly disclosed
- 29 Oct 2026, 16:34 UTCReported by GitHub Advisory · GitHub Advisory
- 29 Oct 2026, 16:35 UTCPicked up by Zero Radar
- 30 Oct 2026, 19:19 UTCNVD reported on it · NVD
Sources 2 reports, oldest first
Official vendor, government CERT or advisory database
- @sylphx/pdf-reader-mcp: HTTP transport accepts unauthenticated requests despite a configured MCP_API_KEYGitHub Advisory · 29 Oct 2026, 16:34 UTC
- CVE-2026-62264NVD · 30 Oct 2026, 19:18 UTC
Technical details
- ID
- CVE-2026-62264 · GHSA-q344-5v34-gm84
- CVSS
- 7.5 / 10
- Disclosed
- 29 Oct 2026, 16:34 UTC
- On Zero Radar
- 29 Oct 2026, 16:35 UTC (1 min after disclosure)
- Last change
- 30 Oct 2026, 19:19 UTC
The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works