critical9.8
CVE-2026-52778
YesWiki has Unsafe eval() in its Formula Calculato, Leading to Remote Code Execution & Denial of Service
Impact
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.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| composer | yeswiki/yeswiki | < 4.6.6 | 4.6.6 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-px5m-h76g-p7p8
- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-px5m-h76g-p7p8
- https://nvd.nist.gov/vuln/detail/CVE-2026-52778
- https://github.com/YesWiki/yeswiki/commit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52
- https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6