# CVE-2025-61673: Karapace is vulnerable to Authentication Bypass


- **Severity:** High 8.6 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 3 Oct 2025
- **Updated:** 6 Oct 2025
- **Also known as:** GHSA-vq25-vcrw-gj53

## What is CVE-2025-61673?

CVE-2025-61673 is a high-severity vulnerability in Aiven-Open karapace, published on 3 Oct 2025. 

### Official description

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.

Weakness: CWE-306 (Missing Authentication for Critical Functionality), CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2025-61673?


## How do I fix CVE-2025-61673?

No fix has been published for CVE-2025-61673 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-61673 being exploited?

There is no known exploitation of CVE-2025-61673 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-61673 and fix it if it is affected.

What it is: CVE-2025-61673 is a high-severity vulnerability in Aiven-Open karapace, published on 3 Oct 2025. 
Exploitation: There is no known exploitation of CVE-2025-61673 in the wild and no public exploit code.

Affected product: Aiven-Open karapace. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-61673/ (Markdown: https://insights.sbomify.com/CVE-2025-61673/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-61673
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-61673
- OSV: https://osv.dev/vulnerability/CVE-2025-61673

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-61673/
Summaries are generated and may contain mistakes; the official description above is the record.