Karapace is vulnerable to Authentication Bypass

published 2025-10-03 13 mo ago modified 2026-10-08 31 d ago also EUVD-2025-33196

cvss: 8.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 33%
public exploits: 0; none known

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.

Patch / fix

fixed in 1 links 2

aiven karapace 5.0.2

github.com/Aiven-Open/karapace#1143 commit
github.com/Aiven-Open/karapace/releases/tag/5.0.2 release

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 13 mo ago (2025-10-06)

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 33% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.6	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L

Affected products

Aiven-Open karapace

Classification

Weakness

CWE-306 Missing Authentication for Critical Functionality
CWE-288 Authentication Bypass Using an Alternate Path or Channel

References

Sources

CVE List CVE-2025-61673
NVD CVE-2025-61673

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary