{"id":"CVE-2026-52778","aliases":["GHSA-px5m-h76g-p7p8"],"url":"https://o3.security/vulnerability/CVE-2026-52778","summary":"YesWiki has Unsafe eval() in Formula Calculator - Remote Code Execution (RCE) & Denial of Service (DoS)","details":"YesWiki is a wiki system written in PHP. Prior to version 4.6.6, an unsafe execution vulnerability exists in the Bazar form field calculator (CalcField.php) of YesWiki. The application attempts to sanitize user-defined mathematical formulas using a complex recursive regular expression before passing them to the PHP eval() function. This implementation is inherently flawed: it is vulnerable to Regular Expression Denial of Service (ReDoS / Stack Overflow) which can crash the server, and it creates a high-risk architecture where any logic bypass directly results in arbitrary PHP code execution. Version 4.6.6 patches the issue.","published":"2026-06-08T18:24:21.671Z","modified":"2026-08-12T03:51:37.996943097Z","cvss":{"score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Packagist","name":"yeswiki/yeswiki","fixedVersion":"4.6.6"}],"fix":{"url":"https://github.com/YesWiki/yeswiki/commit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52","label":"YesWiki/yeswiki@dd2bd8f"},"references":[{"type":"WEB","url":"https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52778.json"},{"type":"ADVISORY","url":"https://github.com/YesWiki/yeswiki/security/advisories/GHSA-px5m-h76g-p7p8"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-52778"},{"type":"FIX","url":"https://github.com/YesWiki/yeswiki/commit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:37.996943097Z"}}