# CVE-2026-50645: Apache CXF denial of service via attachment headers

Source: https://junglewise.ai/threats/cve-2026-50645-apache-cxf-denial-of-service-via-attachment-headers  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-12. Updated: 2026-08-06  
License: CC BY 4.0 with a link back

CVE-2026-50645 · Severity: high · CVSS 7.5 · Published 2026-06-12

Apache CXF, a framework used to build and develop web services, contains a flaw in how it handles message attachments. An attacker can send a specially crafted message with an excessive number of attachment headers, causing the system to consume all available resources. This can lead to a denial-of-service, making the web service unavailable to legitimate users and potentially impacting business operations.

Technologies: [Apache Software Foundation CXF](https://junglewise.ai/threats/technologies/cxf), [org.apache.cxf:cxf-core (Maven)](https://junglewise.ai/threats/technologies/org-apache-cxf-cxf-core). Vendors: [Apache](https://junglewise.ai/threats/vendors/apache), [Apache Software Foundation](https://junglewise.ai/threats/vendors/apache-software-foundation), [Maven](https://junglewise.ai/threats/vendors/maven).

## Quick answers

**Is CVE-2026-50645 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-50645 being exploited in the wild.

**How severe is CVE-2026-50645?** High severity, with a CVSS score of 7.5, published 12 June 2026.

**Which products and versions are affected?** Apache Cxf-Core >= 4.2.0, < 4.2.2; < 4.1.7; Apache Software Foundation CXF 4.2.0 before 4.2.2, all versions before 4.1.7; org.apache.cxf:cxf-core (Maven) ECOSYSTEM:introduced=4.2.0,fixed=4.2.2.

**Is there a fix for CVE-2026-50645?** Yes. org.apache.cxf:cxf-core (Maven): upgrade to 4.2.2 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-50645 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-50645?** Check whether you run Apache Cxf-Core, Apache Software Foundation CXF or org.apache.cxf:cxf-core (Maven) 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.

## How to fix

- org.apache.cxf:cxf-core (Maven): upgrade to 4.2.2 or later

  ```sh
  # set org.apache.cxf:cxf-core to 4.2.2 in your pom.xml or build.gradle
  ```


## Technical details

A resource exhaustion vulnerability (CWE-400) exists in Apache CXF's core deserialization logic. The component does not impose a limit on the number of attachment headers processed per message. A remote, unauthenticated attacker can exploit this by sending a message with a large number of headers, leading to uncontrolled memory or CPU consumption and a Denial of Service (DoS) condition. The issue is resolved in versions 4.2.2 and 4.1.7 by implementing a default limit of 500 attachments per message.

## Affected products

- Apache cxf-core >= 4.2.0, < 4.2.2; < 4.1.7

## Identifiers

- CVE-2026-50645
- GHSA-ghvc-7hp8-2g2v

## Timeline

- 2026-06-11: disclosed: Initial disclosure on oss-security list
- 2026-06-12: advisory: GitHub Advisory published
- 2026-06-12: patched: Patched versions 4.2.2 and 4.1.7 released

## References

- [https://api.github.com/users/julianladisch](https://api.github.com/users/julianladisch)
- [https://github.com/julianladisch](https://github.com/julianladisch)
- [https://api.github.com/users/julianladisch/gists%7B/gist_id%7D](https://api.github.com/users/julianladisch/gists%7B/gist_id%7D)
- [https://api.github.com/users/julianladisch/repos](https://api.github.com/users/julianladisch/repos)
- [https://avatars.githubusercontent.com/u/533612?v=4](https://avatars.githubusercontent.com/u/533612?v=4)
- [https://api.github.com/users/julianladisch/events%7B/privacy%7D](https://api.github.com/users/julianladisch/events%7B/privacy%7D)

## Related threats

- [Apache CXF signature verification bypass in JwsJsonContainerRequestFilter](https://junglewise.ai/threats/cve-2026-50634-apache-cxf-signature-verification-bypass-in)
- [Apache CXF race condition in AbstractOAuthDataProvider](https://junglewise.ai/threats/cve-2026-50631-apache-cxf-race-condition-in-abstractoauthdataprovider)
- [Apache CXF inverted IP binding check in OAuthRequestFilter](https://junglewise.ai/threats/cve-2026-50628-apache-cxf-inverted-ip-binding-check-in-oauthrequestfilter)
- [Apache CXF missing JWT Audience validation in JwtAccessTokenValidator](https://junglewise.ai/threats/cve-2026-50627-apache-cxf-missing-jwt-audience-validation-in)
- [Apache CXF authentication bypass in OAuth2 TokenIntrospectionService](https://junglewise.ai/threats/cve-2026-50623-apache-cxf-authentication-bypass-in-oauth2)