mcp-memory-service's Wildcard CORS with Credentials Enables Cross-Origin Memory Theft

Exploitation

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

CVSS

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

EPSS

• CVE-2026-33010: 0.39% estimated exploitation activity in the next 30 days; percentile 33.68 (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.

Summary When the HTTP server is enabled (MCPHTTPENABLED=true), the application configures FastAPI's CORSMiddleware with alloworigins=[''], allowcredentials=True, allowmethods=[""], and allowheaders=[""]. The wildcard Access-Control-Allow-Origin: header permits any website to read API responses cross-origin. When combined with anonymous access (MCPALLOWANONYMOUSACCESS=true) - the simplest way to get the HTTP dashboard working without OAuth - no credentials are needed, so any malicious website can silently read, modify, and delete all stored memories. Details Vulnerable Code config.py:546 - Wildcard CORS origin default This produces [''] by default, allowing any origin. app.py:274-280 - CORSMiddleware configuration How the Attack Works The wildcard CORS default means every API response includes Access-Control-Allow-Origin: . This tells browsers to allow any website to read the response. When combined with anonymous access (no authentication required), the attack is straightforward: The…

Published by the source

7 Mar 2026, 02:12 UTC

Last modified by the source

13 Jul 2026, 16:42 UTC

Source last checked

26 Oct 2026, 13:37 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-g9rg-8vq5-mpwm

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-g9rg-8vq5-mpwm

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# Patch Next advisory brief: CVE-2026-33010

Advisory: mcp-memory-service's Wildcard CORS with Credentials Enables Cross-Origin Memory Theft
IDs: CVE-2026-33010, GHSA-g9rg-8vq5-mpwm
Record: https://patchnext.com/advisories/cve-2026-33010 (revision 2, source checked 26 Oct 2026, 13:37 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: mcp-memory-service 10.25.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI mcp-memory-service: affected < 10.25.1; fixed in 10.25.1

## Suggested inspection (read-only)
- `python -m pip show mcp-memory-service`: prints the installed version. Run with the environment that serves production active.

## 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 mcp-memory-service.
- 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://osv.dev/vulnerability/GHSA-g9rg-8vq5-mpwm (OSV record GHSA-g9rg-8vq5-mpwm lists affected ranges: PyPI mcp-memory-service >=0 <10.25.1 (fixed))
- Verified: https://github.com/advisories/GHSA-g9rg-8vq5-mpwm (GitHub-reviewed advisory GHSA-g9rg-8vq5-mpwm lists affected ranges: PyPI mcp-memory-service >=0 <10.25.1)

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