CVE-2026-42344

Published: Mag 09, 2026 Last Modified: Mag 09, 2026
ExploitDB:
Other exploit source:
Google Dorks:
MEDIUM 6,3
Source: [email protected]
Attack Vector: network
Attack Complexity: high
Privileges Required: low
User Interaction: none
Scope: changed
Confidentiality: high
Integrity: none
Availability: none

Description

AI Translation Available

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.

367

Time-of-check Time-of-use (TOCTOU) Race Condition

Incomplete
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Other Non-Repudiation
Potential Impacts:
Alter Execution Logic Unexpected State Modify Application Data Modify Files Or Directories Modify Memory Other Hide Activities
Applicable Platforms
All platforms may be affected
Likelihood of Exploit: Medium
View CWE Details
https://github.com/labring/FastGPT/security/advisories/GHSA…
https://github.com/labring/FastGPT/security/advisories/GHSA-cc8x-jrqv-hmwh