CVE-2026-52778

CRITICAL EPSS 42.5%
Published Jun 8, 20263w ago · Modified Jun 17, 20261w ago
9.8 CVSS 3.1
Critical
Find Similar
Published Jun 8, 2026 3w ago
Last Modified Jun 17, 2026 1w ago

Description

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 Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
42.5% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-1333
CWE-94 Improper Control of Generation of Code (Code Injection) Injection

References 3

  • github.com https://github.com/YesWiki/yeswiki/commit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52
  • github.com https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6
  • github.com https://github.com/YesWiki/yeswiki/security/advisories/GHSA-px5m-h76g-p7p8

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.