# CVE-2026-86319: java-json-tools json-patch denial of service in JsonPatch.apply()

Source: https://junglewise.ai/threats/cve-2026-86319-java-json-tools-json-patch-denial-of-service-in-jsonpatch-apply  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-07. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-86319 · Severity: medium · CVSS 5.3 · Published 2026-09-07

json-patch is a Java library that processes JSON Patch documents (RFC 6902) to modify JSON data structures. The library fails to limit the number of operations in a patch request, allowing an attacker to send a request with tens of thousands of operations that consume excessive CPU and memory, blocking the server for extended periods and potentially causing a denial of service.

## Quick answers

**Is CVE-2026-86319 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-86319 being exploited in the wild.

**How severe is CVE-2026-86319?** Medium severity, with a CVSS score of 5.3, published 7 September 2026.

**Which products and versions are affected?** java-json-tools json-patch up to 1.13.

**Is there a fix for CVE-2026-86319?** 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-2026-86319 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-86319?** Check whether anything you run is named in the advisory. 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

The vulnerability is an uncontrolled resource consumption (CWE-400) in the JsonPatch.apply() method, which processes patch operations without enforcing any limit on operation count, timeout, or resource budget. Each patch operation internally calls node.deepCopy(), resulting in O(N×M) complexity where N is the number of operations and M is the document size. An unauthenticated, network-based attacker can exploit this by sending a malicious JSON Patch document containing tens of thousands of operations; proof-of-concept testing shows 50,000 operations consuming 68+ seconds of CPU and quadratic memory growth. The vulnerability affects json-patch up to and including version 1.13, and the maintainers have not yet responded to the initial report.

## Affected products

- java-json-tools json-patch up to 1.13

## Timeline

- 2026-07-29: disclosed: Security issue #167 reported on GitHub
- 2026-09-07: advisory: CVE-2026-86319 published

## References

- [https://github.com/java-json-tools/json-patch/](https://github.com/java-json-tools/json-patch/)
- [https://github.com/java-json-tools/json-patch/issues/167](https://github.com/java-json-tools/json-patch/issues/167)