CVE-2007-4556: Opensymphony Xwork

Medium severity, CVSS 6.8. EPSS: 25.7% chance of exploitation in the next 30 days.

Struts support in OpenSymphony XWork before 1.2.3, and 2.x before 2.0.4, as used in WebWork and Apache Struts, recursively evaluates all input as an Object-Graph Navigation Language (OGNL) expression when altSyntax is enabled, which allows remote attackers to cause a denial of service (infinite loop) or execute arbitrary code via form input beginning with a "%{" sequence and ending with a "}" character.

Affected products

• Opensymphony Xwork: before 1.2.3 (fixed in 1.2.3); from 2.0.0, up to and including 2.0.4

Published 2007-08-28. Last modified 2026-06-16.