CVE-2026-52778: critical vulnerability in yeswiki
YesWiki has Unsafe eval() in Formula Calculator - Remote Code Execution (RCE) & Denial of Service (DoS)
Published · Updated
28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.8epss 0.8%
exploitation probability
0.8%top 44% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
YesWiki · yeswikiRelated CVEs — yeswiki
In the same product, most dangerous first.
CVE-2025-31131HIGHPath Traversal allowing arbitrary read of files in YeswikiEPSS 5.5%CVE-2026-46670CRITICALYesWiki: Unauthenticated SQL InjectionEPSS 2.0%CVE-2025-46347MEDIUMYesWiki Remote Code Execution via Arbitrary PHP File Write and ExecutionEPSS 1.0%CVE-2026-52762HIGHYesWiki: Authenticated (Admin) Server-Side Template Injection to Remote Code Execution via Bazar Semantic TemplatesEPSS 0.8%CVE-2026-52774MEDIUMReflected XSS via Unescaped `id` Parameter in Bazar Widget HTML Attributes in YesWikiEPSS 0.7%CVE-2025-46348CRITICALYesWiki Vulnerable to Unauthenticated Site Backup Creation and DownloadEPSS 0.7%