CVE-2026-68929FastGPT: Unauthenticated WeChat channel hijack and denial of service via shareId-only authorization

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.

CVSS

9.3 CRITICAL (v4.0, CNA)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

Weakness (CWE)

CWE-862, CWE-306

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

GitHub_M

NVD analysis

Deferred

Record last updated

Aug 28, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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