Resource exhaustion in Apache Struts
CVE-2026-73633
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 class: DoS (Denial of Service)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.001
Affected products
- Apache Struts
- Apache Software Foundation Struts — versions 2.1.8, 2.5.0, 6.0.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cwiki.apache.org/confluence/display/WW/S2-072 (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-73633?
- CVE-2026-73633 is a high-severity vulnerability in Apache Struts, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-08-14.
- How severe is CVE-2026-73633?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2026-73633 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.