# CVE-2026-77121: Sonatype Nexus Repository denial of service via oversized POM metadata

Source: https://junglewise.ai/threats/cve-2026-77121-sonatype-nexus-repository-denial-of-service-via-oversized-pom  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-02. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-77121 · Severity: info · Published 2026-09-02

Sonatype Nexus Repository is a software artifact repository manager used by organizations to host and manage Maven packages and dependencies. An authenticated user with deployment permissions could upload a specially crafted Maven project file (POM) containing an oversized metadata field, causing the repository's listing and browsing functions to permanently fail until an administrator manually repairs the data. Only the targeted repository is affected; other repositories and the server remain operational.

Technologies: [Sonatype Nexus Repository](https://junglewise.ai/threats/technologies/nexus-repository). Vendors: [Sonatype](https://junglewise.ai/threats/vendors/sonatype).

## Quick answers

**Is CVE-2026-77121 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77121 being exploited in the wild.

**How severe is CVE-2026-77121?** Informational severity, published 2 September 2026.

**Which products and versions are affected?** Sonatype Nexus Repository 3.95.0 through 3.95.4.

**Is there a fix for CVE-2026-77121?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-77121 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-77121?** Check whether you run Sonatype Nexus Repository at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This vulnerability involves a denial-of-service condition in Sonatype Nexus Repository's Maven metadata handling. An authenticated user with deployment permissions to a hosted Maven repository can upload a POM file containing a malformed or oversized metadata field. The repository's index or metadata parser does not properly validate or limit the size of these fields, causing subsequent attempts to list or browse that specific repository's components to fail. The failure is persistent until manual administrative intervention repairs the corrupted metadata. The attack requires valid deployment credentials and targets only the specific repository receiving the malicious artifact; other repositories are unaffected.

## Affected products

- Sonatype Nexus Repository 3.95.0 through 3.95.4

## Timeline

- 2026-09-02: disclosed

## References

- [https://help.sonatype.com/en/sonatype-nexus-repository-3-95-0-release-notes.html](https://help.sonatype.com/en/sonatype-nexus-repository-3-95-0-release-notes.html)
- [https://support.sonatype.com/hc/en-us/articles/54635665756691/](https://support.sonatype.com/hc/en-us/articles/54635665756691/)

## Related threats

- [Sonatype Nexus Repository privilege escalation in script execution](https://junglewise.ai/threats/cve-2026-77124-sonatype-nexus-repository-privilege-escalation-in-script)
- [Sonatype Nexus Repository 3 SSRF in SSL Certificate Retrieval endpoint](https://junglewise.ai/threats/cve-2026-7494-sonatype-nexus-repository-3-ssrf-in-ssl-certificate-retrieval)
- [Sonatype Nexus Repository improper restriction of authentication attempts](https://junglewise.ai/threats/cve-2026-3329-sonatype-nexus-repository-improper-restriction-of-authentication)
- [An authenticated user with upload permission to a hosted repository can store content that causes arbitrary JavaScript…](https://junglewise.ai/threats/cve-2026-7308-sonatype-nexus-repository-stored-xss-in-html-index-page)
- [Sonatype Nexus Repository reflected XSS](https://junglewise.ai/threats/cve-2026-3438-sonatype-nexus-repository-reflected-xss)