CVE-2026-68929 FastGPT: Unauthenticated WeChat channel hijack and denial of service via shareId-only authorization
Unauthenticated attackers can hijack WeChat channels or cause denial of service by exploiting missing authorization checks on shareId-based endpoints.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-68929?
CVE-2026-68929 is a critical missing authorization vulnerability in labring FastGPT, published on 27 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Which versions are affected by CVE-2026-68929?
How do I fix CVE-2026-68929?
No fix has been published for CVE-2026-68929 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-68929 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-68929 exists.
Public exploit code: 1 proofs of concept on GitHub.
Sources
Also known as GHSA-q4pr-3qpg-9q5v.