CVE-2026-73095
Apache Juneau: Denial of service via unbounded memory allocation in parsers and REST request handling
What happened?
Allocation of Resources Without Limits or Throttling vulnerability in Apache Juneau.
The MessagePack parser, which the REST server enables by default, sizes buffers from length values in the input. An unauthenticated client can send a few bytes that force a multi-gigabyte allocation and an OutOfMemoryError, causing denial of service. Related unbounded allocations in REST request handling (multipart uploads and request reader buffers) are fixed at the same time.
This issue affects Apache Juneau: through 9.2.0.
Users are recommended to upgrade to version 9.2.1, which fixes the issue.
Affected software and versions
| Software | Version information | Fixed version |
|---|---|---|
| org.apache.juneau:juneau-marshallApache Software Foundation | affected: 0 to < 9.2.1 | See vendor advisory |
| org.apache.juneau:juneau-rest-serverApache Software Foundation | affected: 0 to < 9.2.1 | See vendor advisory |
Version information comes from the source record and can include unaffected products and exceptions. Distribution packages may contain backported fixes: an older upstream version alone does not prove a server is affected.
Is it being exploited?
This CVE was not listed in the CISA catalogue at our last retrieval. This does not establish that exploitation is absent.
How to respond
- Confirm the product, installed package version, and any configuration requirements in the vendor advisory.
- Follow the vendor’s remediation or workaround guidance in the references below. Structured fixed-version data is unavailable here; the publisher’s description may include a fix or workaround.
- Restart affected services if required, then verify the running version. Known exploitation may warrant investigation as well as patching.