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.
History

Sat, 09 May 2026 00:00:00 +0000

Type Values Removed Values Added
First Time appeared Labring
Labring fastgpt
Vendors & Products Labring
Labring fastgpt

Fri, 08 May 2026 22:30:00 +0000

Type Values Removed Values Added
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.
Title FastGPT: DNS rebinding TOCTOU bypass in isInternalAddress allows SSRF on all protected endpoints
Weaknesses CWE-367
References
Metrics cvssV3_1

{'score': 6.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-08T22:10:00.875Z

Reserved: 2026-04-26T13:26:14.515Z

Link: CVE-2026-42344

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-05-08T23:16:37.177

Modified: 2026-05-08T23:16:37.177

Link: CVE-2026-42344

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-09T00:00:25Z