MediumVulnerability

CVE-2026-42344: FastGPT DNS rebinding in isInternalAddress() allows internal address bypass

Source: NVD(opens in a new tab)
Identifier: CVE-2026-42344
Published: May 8, 2026
Record updated: October 9, 2026

Known exploitation: Not listed in the CISA Known Exploited Vulnerabilities catalog at the last check.
EPSS: 0.1%

Summary

CVE-2026-42344 affects FastGPT, an AI Agent building platform, in versions 4.14.11 and prior. The isInternalAddress() function in packages/service/common/system/utils.ts is vulnerable to DNS rebinding, a time-of-check to time-of-use flaw: it resolves the hostname with dns.resolve4()/dns.resolve6() and checks the IPs against private ranges, but the HTTP request runs as a separate call with a new DNS resolution, so the record can change between validation and fetch.

Mitigation

The source does not state a fix yet. Check the original advisory for updates.

Details

Scores and exploitation

CVSS score: 6.3(medium)
CVSS vector: 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
EPSS: 0.1%Estimated probability that this CVE is exploited in the next 30 days, from the FIRST Exploit Prediction Scoring System. Read on November 8, 2026.
Disclosure date: May 8, 2026

Weaknesses and techniques

Weakness (CWE): CWE-367
Attack pattern (CAPEC): CAPEC-27

Classification

Attack type: Other
Attack sophistication: Advanced
AI component targeted: Framework
Impact: Confidentiality,
Integrity
Labels: security

How this record was produced

Summaries, mitigations and labels on this page are generated automatically from the source. The linked source is authoritative. The source gives this advisory a description and no title, so the title above is a headline generated from the source text.

Original source: https://nvd.nist.gov/vuln/detail/CVE-2026-42344

First tracked: May 9, 2026 at 02:12 AM ET, from NVD/CVE Database

Classifier: claude-haiku-5-5, prompt v4

Classifier confidence: 85% (self-assessed)

Topics

AI agents

Summary

Mitigation

Topics

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