CVE-2026-42344 — MEDIUM (6.3)

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 is vulnerable to DNS rebinding (TOCTOU — Time-of-Check to Time-of-Use). The function resolves the hostname via dns.resolve4()/dns.resolve6() and checks resolved IPs against private ranges, but the actual HTTP request happens in a separate call with a new DNS resolution, allowing the DNS record to change between validation and fetch. At time of publication, there are no publicly available patches.

CVSS Score

6.3

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-367

References

FAQ

What is CVE-2026-42344?

CVE-2026-42344 is a vulnerability with a CVSS score of 6.3 (MEDIUM). 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 is vulnerable to DNS rebinding (TOCTOU — Time...

How severe is CVE-2026-42344?

CVE-2026-42344 has been rated MEDIUM with a CVSS base score of 6.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-42344?

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