[ANN] CVE-2026-73634: Apache Struts: Unbounded read of a Content Security Policy violation report - S2-073

Severity: moderate

Affected versions:
- Apache Struts (org.apache.struts:struts2-core) 6.0.0 through 6.10.0
- Apache Struts (org.apache.struts:struts2-core) 7.0.0 through 7.2.1

Description:
Uncontrolled resource consumption vulnerability in Apache Struts. An
application that exposes an endpoint collecting Content Security Policy
violation reports reads the submitted report into memory without bounding
how much it will accept, so a single request can exhaust the heap and deny
service to other users. Such endpoints are ordinarily reachable without
authentication. The core distribution maps no such endpoint by default;
applications that do not collect violation reports are not affected.

This issue affects Apache Struts: 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.

Credit:
Michael Mullins (finder)

References:
https://cwiki.apache.org/confluence/display/WW/S2-073
https://www.cve.org/CVERecord?id=CVE-2026-73634


On behalf of the Apache Struts project
Łukasz Lenart