CVE-2026-42344

What it is

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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of data exposure.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-05-08 23:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-24 21:10 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 6.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-05-08 23:16 UTC

Last modified

2026-07-24 21:10 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-367

Record status

Deferred

Attack profile CVSS 3.1 · 6.3

Attack vector

Network

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-42344.md and follow it. Check whether this project is affected by CVE-2026-42344. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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