CVE-2020-15222

Name: CVE-2020-15222
Creator: NVD / NIST
Published: 2020-09-24T17:15:13.117+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 0.87%

Last modified Jun 17, 2026

CVE-2020-15222 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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. EPSS estimates a 0.87% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

EPSS Probability

0.87%

54.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Ory	Fosite	< 0.31.0

References

https://github.com/ory/fosite/commit/0c9e0f6d654913ad57c507dd9a36631e1858a3e9Patch, Third Party Advisory
https://github.com/ory/fosite/security/advisories/GHSA-v3q9-2p3m-7g43Exploit, Third Party Advisory
https://openid.net/specs/openid-connect-core-1_0.html#ClientAuthenticationThird Party Advisory
https://github.com/ory/fosite/commit/0c9e0f6d654913ad57c507dd9a36631e1858a3e9Patch, Third Party Advisory
https://github.com/ory/fosite/security/advisories/GHSA-v3q9-2p3m-7g43Exploit, Third Party Advisory
https://openid.net/specs/openid-connect-core-1_0.html#ClientAuthenticationThird Party Advisory

Timeline

Published: Sep 24, 2020
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-15222?

How severe is CVE-2020-15222?

CVE-2020-15222 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.87% probability of exploitation in the next 30 days.

How do I fix CVE-2020-15222?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-15222?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST