CVE-2020-15222: Ory Fosite

High severity, CVSS 8.1. EPSS: 0.9% chance of exploitation in the next 30 days.

In ORY Fosite (the security first OAuth2 & OpenID Connect framework for Go) before version 0.31.0, when using "private_key_jwt" authentication the uniqueness of the `jti` value is not checked. When using client authentication method "private_key_jwt", OpenId specification says the following about assertion `jti`: "A unique identifier for the token, which can be used to prevent reuse of the token. These tokens MUST only be used once, unless conditions for reuse were negotiated between the parties". Hydra does not seem to check the uniqueness of this `jti` value. This problem is fixed in version 0.31.0.

Affected products

• Ory Fosite: before 0.31.0 (fixed in 0.31.0)

Published 2020-09-24. Last modified 2026-06-17.