CVE-2026-68929: labring FastGPT advisory

Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.

What it is

FastGPT is an open-source LLM platform for building AI applications on a knowledge base. In versions prior to 4.15.2, the WeChat (iLink) share-channel endpoints authorize requests using only the public shareId, with no authenticated identity or team-ownership check. As a result, an unauthenticated attacker who knows a victim team’s shareId can take that team’s WeChat bot offline or hijack the channel to their own bot: the logout endpoint is gated only by an existence check yet wipes the outLink’s stored WeChat token, and the QR-code status endpoint performs no authorization at all and writes attacker-supplied bot credentials into the outLink identified by shareId. By generating a QR for a victim shareId, scanning it with their own WeChat, and calling the status endpoint, an attacker binds the victim team’s app to the attacker’s bot, exposing the app’s private responses, displacing the legitimate binding, and consuming the victim’s resources. The shareId is exposed in every shared chat URL, iframe, and embed, so it is not a secret. This issue is fixed in version 4.15.2.

Description quoted from the CVE record (assigned by GitHub_M, published 2026-08-27).

Weakness: CWE-862: Missing Authorization; CWE-306: Missing Authentication for Critical Function

How it can be exploited

Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability high. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CISA assessment (SSVC): CISA assesses that a public proof of concept exists. Automatable: yes. Technical impact: total.

Public exploit evidence (Exploit Observer)

Also known as: EUVD-2026-67310

VEDAS cluster: VEDAS:DEFINITIVEDESIGN

Exploit Observer links 6 pieces of public exploit code or detection modules that name this CVE or one of its aliases.

Exploit code and modules (6)

Code that names this CVE. A repository can be a working exploit, a scanner, a fake or malware; read it before running anything.

Vulnerability databases and vendor advisories (2)

Catalogue entries, not exploit evidence.

Vulnerability database or vendor advisory: https://euvd.enisa.europa.eu/enisa/EUVD-2026-67310
Vulnerability database or vendor advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-68929

1 more reference returned by Exploit Observer did not name this CVE or an alias, so they are left out.

VEDAS data as of 2026-11-01T17:12 UTC; fetched 2026-11-02.

Live scores

EPSS: 0.004
low predicted chance of attack
VEDAS: 0.986
strong exploit evidence
On CISA KEV: Not listed
Detection rule: Nuclei · Suricata

Who is affected

Product	Affected	Not affected
labring FastGPT	version >= 4.14.10, < 4.14.29 version >= 4.15.0, < 4.15.2	Not stated

Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.

How to fix it

No fixed version or vendor advisory is listed in the CVE record yet. Watch the vendor’s security page.

How to detect it

Nuclei template (active check)

FastGPT - Missing Authorization
FastGPT prior to 4.15.2 authorizes its WeChat (iLink) share-channel endpoints under /api/support/outLink/wechat/ using only the public shareId, with no authenticated identity or team-ownership check. An unauthenticated attacker who knows a victim team’s shareId (exposed in every shared chat URL, iframe and embed) can take the WeChat bot offline via the logout endpoint or hijack the channel to their own bot via the QR-code status endpoint. This template sends a benign request with a random, non-existent shareId; a vulnerable build reaches the share-link lookup without any authentication challenge and returns the invalid-link response, whereas a patched build rejects the request with an authentication error.

Name and description quoted from the template, written by VEDAS.

The template sends 1 request (POST /api/support/outLink/wechat/logout); it decides using word matchers. Severity in the template: high. Marked as not yet verified against a live vulnerable target.

Run it against a host you own or are authorised to test:

bash

nuclei -u https://your-host -t CVE-2026-68929.yaml

Show the template (40 lines)

yaml

id: CVE-2026-68929

info:
  name: "FastGPT - Missing Authorization"
  author: vedas-arpsyndicate
  severity: high
  description: |
    FastGPT prior to 4.15.2 authorizes its WeChat (iLink) share-channel endpoints under
    /api/support/outLink/wechat/ using only the public shareId, with no authenticated identity or
    team-ownership check. An unauthenticated attacker who knows a victim team's shareId (exposed in every
    shared chat URL, iframe and embed) can take the WeChat bot offline via the logout endpoint or hijack
    the channel to their own bot via the QR-code status endpoint. This template sends a benign request with
    a random, non-existent shareId; a vulnerable build reaches the share-link lookup without any
    authentication challenge and returns the invalid-link response, whereas a patched build rejects the
    request with an authentication error.
  reference:
    - https://www.exploit.observer/?keyword=CVE-2026-68929&match=exact
    - https://subdomain.center/?engine=ammonites&keyword=fastgpt&match=exact
  classification:
    cvss-metrics: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
    cvss-score: 9.3
    cve-id: CVE-2026-68929
    cwe-id: CWE-862
  metadata:
    verified: false
  tags: cve,cve2026,fastgpt,auth-bypass,wechat
http:
  - raw:
      - |
        POST /api/support/outLink/wechat/logout HTTP/1.1
        Host: {{Hostname}}
        Content-Type: application/json

        {"shareId":"{{randstr}}"}

    matchers:
      - type: word
        part: body
        words:
          - "linkUnInvalid"

CVE-2026-68929.yaml on GitHub

Suricata rules (network detection)

1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-68929 FastGPT - Missing Authorization WeChat Channel. Add them to your Suricata rule set and reload.

Show the rules

suricata

alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-68929 FastGPT - Missing Authorization WeChat Channel"; flow:established,to_server; http.uri; content:"/api/support/outLink/wechat/"; nocase; fast_pattern; pcre:"/\x2fapi\x2fsupport\x2foutLink\x2fwechat\x2f(?:logout|qrcode\x2fstatus)/i"; classtype:web-application-attack; reference:cve,CVE-2026-68929; reference:url,https://www.exploit.observer/?keyword=CVE-2026-68929&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=fastgpt&match=exact; sid:1079804; rev:1;)

CVE-2026-68929.rules on GitHub

References

Other references

https://github.com/labring/FastGPT/security/advisories/GHSA-q4pr-3qpg-9q5v (x_refsource_CONFIRM)
https://github.com/labring/FastGPT/commit/81d391995b1f9989455267448872ff88bb1f42c9 (x_refsource_MISC)

Other databases

Where this comes from

This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.