CVE-2026-73633: Apache Struts: Unbounded read of a JSON request body

1. In CISA KEV: not seen
2. Exploited (reported): not seen
3. Scanning observed: not seen
4. Proof of concept public1 public GitHub repository (unverified), listed by PoC-in-GitHub16 Aug
5. Not established: not seen

DescriptionNVD

Uncontrolled resource consumption vulnerability in the JSON plugin of Apache Struts. When an application is configured to populate actions from a JSON request body, the plugin reads that body into memory without bounding how much it will accept, so a single request can exhaust the heap and deny service to other users. The plugin's configurable JSON input length limit does not bound this read. The JSON plugin is an optional component; applications that do not use it, or use it without enabling JSON request-body handling, are not affected. This issue affects Apache Struts: from 2.1.8 through 2.3.37, from 2.5.0 through 2.5.33, from 6.0.0 through 6.10.0, from 7.0.0 through 7.2.1. Users are recommended to upgrade to version 6.11.0 or 7.3.0, which fixes the issue.

Exploitation

Unlikely (under 1%). EPSS under 1%, or no score yet.

CISA KEV

Not listed

Public check

No public nuclei template

Weakness

Uncontrolled Resource Consumption · Denial of Service

Vendor

Apache Software Foundation

Published

August 2026

Band

Unlikely (under 1%), August 2026

1. 16 Aug
   PoC-in-GitHub lists 1 public GitHub repository (unverified) PoC-in-GitHub

• NVD entrynvd.nist.gov
• Vendor advisorycwiki.apache.org
• CVE recordcve.org
• Weakness CWE-400cwe.mitre.org