CVE-2011-5021

CVE-2011-5021 is a none vulnerability published on December 29, 2011. PHPIDS before 0.7 does not properly implement Regular Expression Denial of Service (ReDoS) filters, which allows remote attackers to bypass rulesets and add PHP sequences to a file via unspecified vectors.

CVE-2011-5021 was first published in the National Vulnerability Database on December 29, 2011, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

CVE-2011-5021 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 47.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2011-5021, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.