Missing Authentication for Critical Function in @agenticmail/mcp
Priority HIGH 77CWE-306Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-306.
Summary
AgenticMail gives AI agents real email addresses and phone numbers. Prior to version 0.9.27, @agenticmail/mcp exposes a Streamable HTTP transport when started with --http or MCP_HTTP=1. In that mode, the /mcp endpoint accepts requests without any HTTP authentication layer. A remote client can initialize a session and call tools directly. This issue has been patched in version 0.9.27.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00359 29th percentileScored 2026-11-07
Fix Fixed agenticmail (agenticmail): 0.9.27@agenticmail/mcp (npm): 0.9.27
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| agenticmail | agenticmail | before 0.9.27 | 0.9.27 | Patch available | CNA |
| — | @agenticmail/mcp (npm) | before 0.9.27 | 0.9.27 | Patch available | GHSA-63gr-g7jc-v8rg |
- agenticmail Vendoragenticmail Affected before 0.9.27 Fixed in 0.9.27 Patch available CNA
- @agenticmail/mcp (npm) Vendor— Affected before 0.9.27 Fixed in 0.9.27 Patch available GHSA-63gr-g7jc-v8rg
Remediation
- Fix · CNA agenticmail (agenticmail) Fixed in 0.9.27
- Fix · GHSA-63gr-g7jc-v8rg @agenticmail/mcp (npm) Fixed in 0.9.27 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-50287
- 2026-10-03 Alias added: GHSA-63gr-g7jc-v8rg
References
Other 7
- https://github.com/agenticmail/agenticmail/security/advisories/GHSA-63gr-g7jc-v8rg
- https://github.com/agenticmail/agenticmail/commit/7b9b05d973676e9f3d097c08b8e649f59bfc15d0
- https://github.com/agenticmail/agenticmail/commit/7d1791da7c8c8bd4e70d7081db48e18ab55f6736
- https://github.com/agenticmail/agenticmail
- https://github.com/agenticmail/agenticmail/blob/7b9b05d973676e9f3d097c08b8e649f59bfc15d0/CHANGELOG.md?plain=1#L10
- https://github.com/agenticmail/agenticmail/blob/7b9b05d973676e9f3d097c08b8e649f59bfc15d0/packages/mcp/README.md?plain=1#L13
- https://github.com/agenticmail/agenticmail/blob/7b9b05d973676e9f3d097c08b8e649f59bfc15d0/packages/mcp/src/index.ts#L311
More agenticmail vulnerabilities
- TI-2026-41399 AgenticMail: Cross-agent task authorization bypass in AgenticMail API CVSS 4.0HIGH 7.1
- TI-2026-41400 Missing authentication in agenticmail @agenticmail/core CVSS 4.0HIGH 8.2
- TI-2026-34838 AgenticMail API/storage and outbound relay hardening CVSS 3.1HIGH 8.2
Sources
- CVE-2026-50287 · CVE Program
- CVE-2026-50287 · NVD
- FIRST EPSS
- GHSA-63gr-g7jc-v8rg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences