What is CVE-2026-73631?

CVE-2026-73631 is a medium-severity vulnerability in Apache Struts, classified under CWE-567. CVSS score: 4.3/10. Published 2026-08-15.

How severe is CVE-2026-73631?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Vulnerability in Apache Struts

CVE-2026-73631

Exposure of data element to wrong session vulnerability in the JSON plugin of Apache Struts. Per-request parsing state could be shared across concurrent requests, allowing data associated with one request to become observable in another, and configured parsing limits not to be enforced as intended. Populating actions from a JSON request body is not enabled by default; applications that do not use the JSON plugin are not affected. This issue affects Apache Struts: 7.2.1. Users are recommended to upgrade to version 7.3.0, which fixes the issue.

Published 2026-08-15 · last modified 2026-08-18.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.004 · change: +0.001

Affected products

Apache Struts — versions 7.2.1
Apache Software Foundation Struts — versions 7.2.1

Weakness classification (CWE)

CWE-567

References

cwiki.apache.org/confluence/display/WW/S2-070 (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2026-73631?: CVE-2026-73631 is a medium-severity vulnerability in Apache Struts, classified under CWE-567. CVSS score: 4.3/10. Published 2026-08-15.
How severe is CVE-2026-73631?: Medium severity. CVSS v3 base score is 4.3 out of 10.