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Critical 9.8Published Jun 8, 2026

CVE-2026-52778YesWiki has Unsafe eval() in Formula Calculator - Remote Code Execution (RCE) & Denial of Service (DoS)

Updated under an hour ago ()

Does this affect you?

It affects yeswiki. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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
9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-94, CWE-1333
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
GitHub_M
NVD analysis
Deferred
Record last updated
Jun 9, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
YesWiki yeswiki
yeswiki:yeswiki (from the name)
before 4.6.6
CNA record

References

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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