CVE-2026-12746 Dancer2::Plugin::Auth::OAuth::Provider versions before 0.23 for Perl do not support the OAuth 2.0 state parameter
Attackers can hijack user sessions by exploiting missing OAuth state validation, linking their identity to victim accounts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-12746?
CVE-2026-12746 is a high-severity vulnerability in BIAFRA Dancer2::Plugin::Auth::OAuth::Provider, published on 4 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Dancer2::Plugin::Auth::OAuth::Provider versions before 0.23 for Perl do not support the OAuth 2.0 state parameter.
The authentication_url method builds the provider authorization redirect without issuing a state value, and the callback method exchanges the callback code and registers the resulting token into the session without verifying that the callback corresponds to an authorization request this session initiated.
Any application that uses this plugin for OAuth 2.0 login is exposed to login cross-site request forgery: because the callback is not bound to the session that began the flow, an attacker who starts an authorization with their own provider account can deliver the resulting callback to a victim, causing the victim's session to complete the attacker's authorization and associating the attacker's provider identity and access token with that session. Where the application persists this as an account link, the attacker may retain access to the victim's account through their own provider credentials.
Weakness: CWE-352
Which versions are affected by CVE-2026-12746?
How do I fix CVE-2026-12746?
No fix has been published for CVE-2026-12746 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-12746 being exploited?
There is no known exploitation of CVE-2026-12746 in the wild and no public exploit code.
Sources
Also known as GHSA-3f6x-q3gv-gmfc.