CVE-2026-42345 — HIGH (7.7)

Vulnerability 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.

CVSS Score

7.7

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-918

References

https://github.com/labring/FastGPT/security/advisories/GHSA-jhqw-944x-xh94

FAQ

What is CVE-2026-42345?

CVE-2026-42345 is a vulnerability with a CVSS score of 7.7 (HIGH). 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 fullU...

How severe is CVE-2026-42345?

CVE-2026-42345 has been rated HIGH with a CVSS base score of 7.7/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42345?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.