CVE-2025-27370
OpenID Connect Core through 1.0 errata set 2 allows audience injection in certain situations....
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.9
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.
- Record
CVE-2025-27370- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N - Weakness
- CWE-305
- Updated
- 2026-11-02
EUVDEUVD-2025-5571
6.9
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.
- Record
EUVD-2025-5571- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-pcj4-9fcj-56c8
6.9
OpenID Connect Core through 1.0 errata set 2 allows audience injection in certain situations....
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.
- Record
GHSA-pcj4-9fcj-56c8- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N - Weakness
- CWE-305, CWE-863
- Updated
- 2026-11-02
NVD
6.9
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.
- Record
CVE-2025-27370- CVSS 3.1
- 6.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:H/A:N - Weakness
- CWE-305
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-27370 is a medium vulnerability (CVSS 6.9) in Openid Connect, published March 3, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.34%, the 28th percentile. No source names a fixed version.
References
openid.net/wp-content/uploads/2025/01/OIDF-Responsible-Disclosure-Notice-on-Security-Vulnerability-for-private_key_jwt.pdf
openid.net/notice-of-a-security-vulnerability
talks.secworkshop.events/osw2025/talk/R8D9BS
github.com/OWASP/ASVS/issues/2678
eprint.iacr.org/2025/629
nvd.nist.gov/vuln/detail/CVE-2025-27370
github.com/advisories/GHSA-pcj4-9fcj-56c8