AWS MCP Gateway Registry SSRF Fix Requires Stored-Address Review
Tech GuruQuick Answer
Upgrade to 1.35.0 or later and review existing registered upstream addresses. Investigate unexpected registrations and changes; review attached cloud-role activity and rotate credentials when the log review cannot rule out unexpected activity.
Confirm Scope And Apply The Supported Remediation
What to do now: Record registry and auth-server versions, registration permissions, upstream destinations, outbound connectivity and attached cloud roles. Match the inclusive 1.0.3–1.34.0 range and identify users able to register or modify servers. Internal-service or metadata exposure depends on the deployment network. Apply 1.35.0 or later, including equivalent fixes in forks. Correct or remove unintended stored upstream addresses. Until patched, restrict registration and modification to trusted accounts, limit component egress, require IMDSv2 on EC2 and minimize attached-role permissions. Verify the running version and rejection of disallowed upstream addresses using approved tests. Review logs across the affected deployment period; preserve configuration changes, role activity and any credential rotation evidence.
Last verified: 2026-11-12 UTC. Recheck the authoritative advisory and supported distribution channel before changing production.
Scope And Authority
| Product scope | Amazon mcp-gateway-registry server registration and update API |
|---|---|
| Advisory | 2026-180-AWS / GHSA-fc39-fwh3-wv5r |
| CVE | CVE-2026-125926 |
| Authoritative release date | November 11, 2026 at 13:00 PST (21:00 UTC), from AWS bulletin 2026-180-AWS. |
| Authority revision date | No separate revision date is provided by the authority. |
| Affected versions | mcp-gateway-registry 1.0.3 through 1.34.0 inclusive. The caller must be authenticated and able to register or modify a server. |
| Fixed version | mcp-gateway-registry 1.35.0 or later |
| CVSS base score | 8.5 (CVSS v3.1 base score, project advisory) |
| CVSS severity | High |
| Exploitation status | The cited AWS and project advisories do not confirm exploitation in the wild.; no exploitation claim is inferred. |
What Changed
AWS discloses SSRF through unvalidated server upstream addresses. The fix validates new or modified registrations, but existing stored configurations require review.
What To Validate Now
- Inventory. Record registry and auth-server versions, registration permissions, upstream destinations, outbound connectivity and attached cloud roles.
- Establish applicability. Match the inclusive 1.0.3–1.34.0 range and identify users able to register or modify servers. Internal-service or metadata exposure depends on the deployment network.
- Remediate. Apply 1.35.0 or later, including equivalent fixes in forks. Correct or remove unintended stored upstream addresses. Until patched, restrict registration and modification to trusted accounts, limit component egress, require IMDSv2 on EC2 and minimize attached-role permissions.
- Validate. Verify the running version and rejection of disallowed upstream addresses using approved tests. Review logs across the affected deployment period; preserve configuration changes, role activity and any credential rotation evidence.
- Retain evidence. Preserve asset and owner identifiers, the applicability decision, before-and-after versions, change approval, installation output, validation results, and any exception or rollback record.
Operational Cautions
The upgrade leaves older registrations unchanged. The separate authorization fix in 1.25.0 is insufficient for this SSRF flaw. Network restrictions can disrupt legitimate tools; validate required destinations before enforcement.
Evidence To Retain
- Exact product, release stream, package or application version, enabled feature, environment, and accountable owner.
- UTC timestamps, authority revision, approved change record, installer or package-manager output, and resulting version.
- Relevant logs and monitoring evidence, test results, exceptions, compensating controls, and rollback decisions.
Related TechGeeks Resources
Authoritative References
Correction policy: If the authority changes affected versions, fixed versions, severity, exploitation information, mitigations, or required action, TechGeeks will update this notice and its verification date.
