Vulnerability in Openid Connect
CVE-2025-27370
OpenID Connect Core through 1.0 errata set 2 allows audience injection in certain situations. When the private_key_jwt authentication mechanism is used, a malicious Authorization Server could trick a Client into writing attacker-controlled values into the audience, including token endpoints or issuer identifiers of other Authorization Servers. The malicious Authorization Server could then use these private key JWTs to impersonate the Client.
EPSS: 0.003 (24.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N.
Affected products
- Openid Connect — versions 0
Weakness classification (CWE)
Public proof-of-concept exploits
References
Frequently asked questions
- What is CVE-2025-27370?
- CVE-2025-27370 is a medium-severity vulnerability in Openid Connect, classified under Authentication Bypass by Primary Weakness. CVSS score: 6.9/10. Published 2025-03-03.
- How severe is CVE-2025-27370?
- Medium severity. CVSS v3 base score is 6.9 out of 10.
- Is CVE-2025-27370 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.