{"cve":"CVE-2007-4556","nvd":{"published":"2007-08-28T01:17:00.000","modified":"2026-06-16T22:44:19.150","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["http://forums.opensymphony.com/ann.jspa?annID=54","http://issues.apache.org/struts/browse/WW-2030","http://jira.opensymphony.com/browse/XW-544","http://jira.opensymphony.com/secure/ReleaseNote.jspa?projectId=10050&styleName=Html&version=21701","http://jira.opensymphony.com/secure/ReleaseNote.jspa?projectId=10050&styleName=Html&version=21706"],"products":["opensymphony:xwork"],"source":"nvd","synced_at":"2026-10-19T19:48:28.501292361+00:00"},"epss":{"cve":"CVE-2007-4556","score":0.25749,"percentile":0.9797,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-h7mf-qrm9-2848","url":"https://osv.dev/vulnerability/GHSA-h7mf-qrm9-2848","summary":"OpenSymphony XWork vulnerable to improper input validation","modified":"2024-11-30T05:49:41.112357Z","packages":[{"ecosystem":"Maven","name":"opensymphony:xwork","purl":"pkg:maven/opensymphony/xwork","ranges":["<1.2.3"],"fixed":["1.2.3"]},{"ecosystem":"Maven","name":"opensymphony:xwork","purl":"pkg:maven/opensymphony/xwork","ranges":[">=2.0.0 <2.0.4"],"fixed":["2.0.4"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}