@sylphx/pdf-reader-mcp: HTTP transport accepts unauthenticated requests despite a configured MCP_API_KEY

Exploitation

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

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS

• CVE-2026-62264: 0.45% estimated exploitation activity in the next 30 days; percentile 39.32 (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.

Impact When `@sylphx/pdf-reader-mcp` is run as an HTTP server (`MCP_TRANSPORT=http`), it reads the `MCP_API_KEY` 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 `MCP_API_KEY` reasonably believed the server was protected when it was not. This affects only the opt-in HTTP transport; the default `stdio` transport…

Published by the source

29 Oct 2026, 16:34 UTC

Last modified by the source

29 Oct 2026, 16:45 UTC

Source last checked

30 Oct 2026, 06:00 UTC

1. Revision 2 · amended · 30 Oct 2026

   Amended from osv record GHSA-q344-5v34-gm84

2. Revision 1 · created · 29 Oct 2026

   Published from ghsa record GHSA-q344-5v34-gm84

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# Patch Next advisory brief: CVE-2026-62264

Advisory: @sylphx/pdf-reader-mcp: HTTP transport accepts unauthenticated requests despite a configured MCP_API_KEY
IDs: CVE-2026-62264, GHSA-q344-5v34-gm84
Record: https://patchnext.com/advisories/cve-2026-62264 (revision 2, source checked 30 Oct 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @sylphx/pdf-reader-mcp 3.0.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @sylphx/pdf-reader-mcp: affected >= 2.2.0, < 3.0.1; fixed in 3.0.1

## Suggested inspection (read-only)
- `npm ls @sylphx/pdf-reader-mcp --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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 @sylphx/pdf-reader-mcp.
- 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-q344-5v34-gm84 (GitHub-reviewed advisory GHSA-q344-5v34-gm84 lists affected ranges: npm @sylphx/pdf-reader-mcp >=2.2.0 <3.0.1)
- Verified: https://osv.dev/vulnerability/GHSA-q344-5v34-gm84 (OSV record GHSA-q344-5v34-gm84 lists affected ranges: npm @sylphx/pdf-reader-mcp >=2.2.0 <3.0.1 (fixed))

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