---
id: CVE-2025-61673
title: Karapace is an open-source implementation of Kafka REST and Schema Registry
summary: >-
  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
  witho…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L'
cwe:
  - CWE-288
  - CWE-306
published: '2025-10-03'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:10:00.563'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-61673'
references:
  - url: >-
      https://github.com/Aiven-Open/karapace/pull/1143/commits/c4038e9ce9fa504b433d59ac2944e337292922c7
    label: security-advisories@github.com
  - url: 'https://github.com/Aiven-Open/karapace/releases/tag/5.0.2'
    label: security-advisories@github.com
  - url: >-
      https://github.com/Aiven-Open/karapace/security/advisories/GHSA-vq25-vcrw-gj53
    label: security-advisories@github.com
tags:
  - nvd
epss: 0.00394
epssPercentile: 0.31403
ingestedAt: '2026-10-08T22:11:53.778Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.