CVE-2026-42345 Details
Description
FastGPT is an AI Agent building platform. In versions 4.14.11 and prior, FastGPT's isInternalAddress() function in packages/service/common/system/utils.ts blocks cloud metadata endpoints using a fullUrl.startsWith() check against a hardcoded list. This check can be bypassed using at least 7 different URL encoding techniques, all of which resolve to the same cloud metadata service but do not match the blocklist patterns. Additionally, the broader private IP check (isInternalIPv4/isInternalIPv6) is disabled by default because CHECK_INTERNAL_IP defaults to false (not 'true'), so these bypasses reach the metadata endpoint without any further validation. At time of publication, there are no publicly available patches.
A server-side request forgery (SSRF) vulnerability has been identified in FastGPT versions through 4.14.11. The issue arises in the 'isInternalAddress()' function, which is supposed to block access to cloud metadata endpoints. However, this block can be bypassed using at least seven different URL encoding techniques that evade the hardcoded blocklist while still resolving to the same metadata service. Furthermore, the function's default settings allow these bypasses to reach the metadata endpoint without proper validation. As a result, attackers can access sensitive cloud metadata, including IAM credentials and instance information.
Developers can patch this vulnerability by updating the 'isInternalAddress()' function to resolve hostnames to IP addresses before checking against the blocklist. Alternatively, the 'CHECK_INTERNAL_IP' environment variable can be set to 'true' to enable private IP checks by default.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed May 8, 2026CISA-ADP
Assessed May 13, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/labring/FastGPT/security/advisories/GHSA-jhqw-944x-xh94 | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-918 | Server-Side Request Forgery (SSRF) | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| labring FastGPT | All versions |
CPE
Remediation
| |
Change History
4 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 24, 2026 | CVE Translated | [email protected] |
| Jun 17, 2026 | CVE Modified | [email protected] |
| Jun 17, 2026 | CVE Modified | CISA-ADP |
| May 8, 2026 | New CVE Received | [email protected] |