Auth bypass in Aiven-Open Karapace
CVE-2025-61673
Karapace is an open-source implementation of Kafka REST and Schema Registry. Versions 5.0.0 and 5.0.1 contain an authentication bypass vulnerability when configured to use OAuth 2.0 Bearer Token authentication. If a request is sent without an Authorization header, the token validation logic is skipped entirely, allowing an unauthenticated user to read and write to Schema Registry endpoints that should otherwise be protected. This effectively renders the OAuth authentication mechanism ineffective. This issue is fixed in version 5.0.2.
EPSS: 0.004 (29.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L.
Affected products
- Aiven-open Karapace — versions >= 5.0.0, < 5.0.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2025-61673?
- CVE-2025-61673 is a high-severity vulnerability in Aiven-Open Karapace, classified under Authentication Bypass Using an Alternate Path or Channel. CVSS score: 8.6/10. Published 2025-10-03.
- How severe is CVE-2025-61673?
- High severity. CVSS v3 base score is 8.6 out of 10.
- Is CVE-2025-61673 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.