CVE-2026-61646 labring CVE debrief

Who should care

Defenders responsible for FastGPT deployments, particularly those with untrusted workflows, should assess exposure and validate the configuration of HTTP request nodes. This includes reviewing the current workflow configurations, verifying the access controls in place, and ensuring that the SSRF guard is properly configured to prevent unauthorized access to sensitive services.

Why it matters

The SSRF vulnerability in FastGPT allows authenticated users to access sensitive internal services, cloud metadata, and loopback services, potentially leading to unauthorized information disclosure.

• Authenticated users can access sensitive internal services
• Cloud metadata may be exposed to authenticated users
• Loopback services may be accessible to authenticated users
• Internal services may be reachable through SSRF

Technical summary

The FastGPT platform's shared SSRF guard validates only the initial request URL before handing the request to axios, which follows redirects by default. An authenticated workflow user can configure an HTTP request node to call an attacker-controlled public URL that redirects to cloud metadata, loopback, or internal services that the guard would block on direct request. This issue allows the attacker to access sensitive internal services, potentially leading to unauthorized information disclosure. The vulnerability is fixed in version 4.15.0-beta5.

Defensive priority

Defenders should prioritize verifying exposure of FastGPT instances to untrusted workflows and validating the configuration of HTTP request nodes.

Recommended defensive actions

• Verify exposure of FastGPT instances to untrusted workflows
• Validate the configuration of HTTP request nodes
• Update to version 4.15.0-beta5 or later
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the SSRF vulnerability in FastGPT versions before 4.15.0-beta5. The issue allows an authenticated workflow user to configure an HTTP request node to call an attacker-controlled public URL that redirects to cloud metadata, loopback, or internal services.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.