Apache Struts JSON Plugin Unbounded Input Ceiling (vs <6.11.0/7.3.0)
CVE-2026-73633 Published on August 14, 2026
Apache Struts: Unbounded read of a JSON request body
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.
Vulnerability Analysis
CVE-2026-73633 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
What is a Resource Exhaustion Vulnerability?
The software does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.
CVE-2026-73633 has been classified to as a Resource Exhaustion vulnerability or weakness.
Products Associated with CVE-2026-73633
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Affected Versions
Apache Software Foundation Apache Struts:- Version 2.1.8, <= 2.3.37 is affected.
- Version 2.5.0, <= 2.5.33 is affected.
- Version 6.0.0, <= 6.10.0 is affected.
- Version 7.0.0, <= 7.2.1 is affected.