Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1000 CNY

100.0%
Buy Us a Coffee

CVE-2026-42344— FastGPT: DNS rebinding TOCTOU bypass in isInternalAddress allows SSRF on all protected endpoints

CVSS 6.3 · Medium EPSS 0.03% · P8
Get alerts for future matching vulnerabilitiesLog in to subscribe

I. Basic Information for CVE-2026-42344

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
FastGPT: DNS rebinding TOCTOU bypass in isInternalAddress allows SSRF on all protected endpoints
Source: NVD (National Vulnerability Database)
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.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
Source: NVD (National Vulnerability Database)
Vulnerability Type
检查时间与使用时间(TOCTOU)的竞争条件
Source: NVD (National Vulnerability Database)
Vulnerability Title
FastGPT 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
FastGPT是labring开源的一款基于大语言模型的开源知识库问答系统。 FastGPT 4.14.11及之前版本存在安全漏洞，该漏洞源于isInternalAddress函数存在DNS重新绑定漏洞，可能导致DNS记录在验证和获取之间发生变化。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
labringFastGPT <= 4.14.11 -

II. Public POCs for CVE-2026-42344

#POC DescriptionSource LinkShenlong Link
AI-Generated POCPremium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-42344

请登录查看更多情报信息。

Same Patch Batch · labring · 2026-05-08 · 6 CVEs total

CVE-2026-423029.8 CRITICALFastGPT: Unauthenticated Remote Code Execution (RCE) via code-server Misconfiguration in a
CVE-2026-423457.7 HIGHFastGPT: Cloud metadata endpoint SSRF protection bypass via port specification, IPv6 mappi
CVE-2026-442846.3 MEDIUMFastGPT: Stored MCP tool URL SSRF in FastGPT workflow execution
CVE-2026-42343FastGPT: Uncontrolled Resource Consumption leading to Sandbox Exhaustion
CVE-2026-44286FastGPT: SSRF Vulnerability in Laf Workflow Node via Missing Internal Address Validation

IV. Related Vulnerabilities

Same product: FastGPT
Same vendor: labring
Same weakness: CWE-367

V. Comments for CVE-2026-42344

No comments yet

Leave a comment