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CVE-2026-52778

CRITICAL Exploitation: PoC
9.8
CVSS 3.1
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.

Metadata

CVE ID
CVE-2026-52778
State
PUBLISHED
Assigner
GitHub_M
Reserved
2026-06-08 17:13 UTC
Published
2026-06-08 18:24 UTC
Last updated
2026-06-09 15:56 UTC
Primary CWE
CWE-94
CWE-94: Improper Control of Generation of Code ('Code Inject…
Vendor / Product
YesWiki / yeswiki
Sources
cve.org  ·  NVD

Severity & Metrics

9.8 CRITICAL CVSS 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC — CISA Coordinator
Exploitation
PoC
Automatable
yes
Tech. Impact
total
Affected products (1)
VendorProductPlatformVersions
YesWiki yeswiki — < 4.6.6
Weakness (CWE)
CWESourceDescription
CWE-1333 cna CWE-1333: Inefficient Regular Expression Complexity
CWE-94 cna CWE-94: Improper Control of Generation of Code ('Code Injection')
CVSS scores (1)
ScoreSeverityVersionSourceVector
9.8 CRITICAL 3.1 cna CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
References (3)
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