Vulnerability · Published Sep 25, 2026 · Assigned by GitHub_M
CVE-2026-92161FriendsOfFlarum OAuth: Unauthenticated account takeover via unverified email trust in Discord OAuth provider
Critical 9.8
In plain English
A critical-severity insufficient verification of data authenticity in oauth from FriendsOfFlarum. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
FriendsOfFlarum OAuth allows users to log in to Flarum with GitHub, Twitter, Facebook, and other providers. Prior to 1.7.4 and 2.0.0-beta.4, the Discord OAuth provider does not check the verified field returned for an OAuth email before passing the address to Flarum core as trusted through provideTrustedEmail(). When Discord sign-in is enabled, an unauthenticated attacker who knows the email address of a Flarum user can configure a Discord account with that unverified address and a verified phone number, then sign in to cause Flarum to match the trusted address, link the attacker-controlled Discord identity to the existing user, and authenticate as the victim without a password or victim interaction. Exploitation requires that the victim's email address is not already associated with a Discord account, and it can compromise administrator accounts. Other bundled providers were not confirmed to be practically exploitable by this method because their relevant authentication flows return only verified or confirmed email addresses. This issue is fixed in versions 1.7.4 and 2.0.0-beta.4.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | fof/oauth | 1.7.4 | GHSA-g7vj-c29h-3h5m |
| Packagist | fof/oauth | 2.0.0-beta.4 | GHSA-g7vj-c29h-3h5m |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| FriendsOfFlarum | oauth | < 1.7.4>= 2.0.0-beta.1, < 2.0.0-beta.4 |
Weakness: CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References
- https://github.com/FriendsOfFlarum/oauth/security/advisories/GHSA-g7vj-c29h-3h5m x_refsource_CONFIRM
- https://github.com/FriendsOfFlarum/oauth/commit/baca3466b3b7be51c70a7e0ba966901aefeb344a x_refsource_MISC
- https://github.com/FriendsOfFlarum/oauth/commit/bb4bf376832e6bb68c579715d2a4b5a92c4a2567 x_refsource_MISC
- https://github.com/FriendsOfFlarum/oauth/releases/tag/1.7.4 x_refsource_MISC
- https://github.com/FriendsOfFlarum/oauth/releases/tag/2.0.0-beta.4 x_refsource_MISC