Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:L) | Low complexity |
| Privileges required (PR:L) | Low privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:C) | Scope changed: impact spreads beyond the component |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:N) | No integrity impact |
| Availability (A:N) | No availability impact |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
About Fastgpt
CVE-2026-34163 affects Fastgpt, a product from Fastgpt. Before acting, confirm where Fastgpt runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: FastGPT is an AI Agent building platform. Prior to version 4.14.9.5, FastGPT's MCP (Model Context Protocol) tools endpoints (/api/core/app/mcpTools/getTools and /api/core/app/mcpTools/runTool) accept a user-supplied URL parameter and make server-side HTTP requests to it without validating whether the URL points to an internal/private network address. Although the application has a dedicated isInternalAddress() function for SSRF protection (used in other endpoints like the HTTP workflow node), the MCP tools endpoints do not call this function. An authenticated attacker can use these endpoints to scan internal networks, access cloud metadata services, and interact with internal services such as MongoDB and Redis. This issue has been patched in version 4.14.9.5.
The weakness class is Server Side Request Forgery. The server can be made to send requests to internal or arbitrary systems.
Based on its CVSS vector, the flaw can be reached over the network, needs some level of access, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Fastgpt |
| Affected versions | Fastgpt before 4.14.9.5 |
| Published | Mar 31, 2026 |
| Last modified | Jul 24, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Fastgpt and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Fastgpt named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Fastgpt to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-918: Server Side Request Forgery More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
FastGPT is an AI Agent building platform. Prior to version 4.14.9.5, the FastGPT HTTP tools testing endpoint (/api/core/app/httpTools/runTool) is exposed without any authentication. This endpoint acts as a full HTTP proxy — it accepts a user-supplied baseUrl, toolPath, HTTP method, custom headers, and body, then makes a server-side HTTP request and returns the complete response to the caller. This issue has been patched in version 4.14.9.5.
FastGPT is an AI Agent building platform. In versions 4.14.8.3 and below, the fastgpt-preview-image.yml workflow is vulnerable to arbitrary code execution and secret exfiltration by any external contributor. It uses pull_request_target (which runs with access to repository secrets) but checks out code from the pull request author's fork, then builds and pushes Docker images using attacker-controlled Dockerfiles. This also enables a supply chain attack via the production container registry. A patch was not available at the time of publication.
FastMCP is a Pythonic way to build MCP servers and clients. Prior to version 3.2.0, the OpenAPIProvider in FastMCP exposes internal APIs to MCP clients by parsing OpenAPI specifications. The RequestDirector class is responsible for constructing HTTP requests to the backend service. A vulnerability exists in the _build_url() method. When an OpenAPI operation defines path parameters (e.g., /api/v1/users/{user_id}), the system directly substitutes parameter values into the URL template string without URL-encoding. Subsequently, urllib.parse.urljoin() resolves the final URL. Since urljoin() interprets ../ sequences as directory traversal, an attacker controlling a path parameter can perform path traversal attacks to escape the intended API prefix and access arbitrary backend endpoints. This results in authenticated SSRF, as requests are sent with the authorization headers configured in the MCP provider. This issue has been patched in version 3.2.0.
Server-side request forgery (ssrf) in Azure Cloud Shell allows an unauthorized attacker to elevate privileges over a network.
Server-side request forgery (ssrf) in Azure Databricks allows an unauthorized attacker to elevate privileges over a network.
Altec DocLink (now maintained by Beyond Limits Inc.) version 4.0.336.0 exposes insecure .NET Remoting endpoints over TCP and HTTP/SOAP via Altec.RDCHostService.exe using the ObjectURI "doclinkServer.soap". The service does not require authentication and is vulnerable to unsafe object unmarshalling, allowing remote attackers to read arbitrary files from the underlying system by specifying local file paths. Additionally, attackers can coerce SMB authentication via UNC paths and write arbitrary files to server locations. Because writable paths may be web-accessible under IIS, this can result in unauthenticated remote code execution or denial of service through file overwrite.
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