CVE-2026-52778

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.

Overview

State

—

Assigner (CNA)

—

CVSS severity

critical

CVSS score

9.8 / 10

CVSS vector

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Effective score

9.8 / 10 CRITICAL source: CNA overview

CWE(s)

—

Reserved

—

Published

—

Last updated

—

Source

https://www.tenable.com/cve/CVE-2026-52778

Linked Threat

CVE-2026-52778 — CVE-2026-52778

NVD triage scoring NVD CVE 2.0

Layer NVD adds on top of the CNA's CVE record — published / last-modified timestamps, exploitability / impact subscores, and the FIRST.org EPSS probability that this CVE will be exploited in the wild in the next 30 days.

NVD published

2026-06-08 19:16:46 UTC

NVD last modified

2026-06-17 10:57:53 UTC

NVD CVSS v3.1

9.8 / 10 CRITICAL source: security-advisories@github.com

NVD CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitability subscore

3.9 / 10

Impact subscore

5.9 / 10

EPSS score

0.0056 (probability of exploitation in next 30 days)

EPSS percentile

42.45% vs all CVEs — higher = more likely to be exploited, as of 2026-06-28

NVD-assigned CWE(s): CWE-94, CWE-1333 (differs from the CNA list above)

European Union Vulnerability Database ENISA EUVD

ENISA's official EU repository for curated vulnerability intelligence. Carries a separate identifier (EUVD-YYYY-NNNN) and frequently exposes an earlier-published description + CVSS than NVD does.

EUVD ID

EUVD-2026-35181

Assigner

GitHub_M

Published

Jun 8, 2026, 6:24:21 PM

Updated

Jun 9, 2026, 3:56:22 PM

EUVD base score (CVSS 3.1)

9.8 / 10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EUVD-reported EPSS

0.5600

Vendors

YesWiki

Products

yeswiki (< 4.6.6)

Aliases

GHSA-px5m-h76g-p7p8

ENISA 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.

Vendor references (0)

References embedded in the original CVE record by the assigning CNA.

None in the CVE record.

Web references (5)

DuckDuckGo results ranked by threat-intel / vendor advisory domains. Generated by the 🔎 Find references (web) button above — same flow as the Remediations search.

• https://github.com/YesWiki/yeswiki/commit/dd2bd8fb099de0d21504bda8a810693b3fcb8e52 tenable:github.com
• https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6 tenable:github.com
• https://github.com/YesWiki/yeswiki/security/advisories/GHSA-px5m-h76g-p7p8 tenable:github.com
• https://nvd.nist.gov/vuln/detail/CVE-2026-52778 tenable:nvd.nist.gov
• https://www.cve.org/CVERecord?id=CVE-2026-52778 tenable:www.cve.org

Remediations are stored against the linked Threat row; the list below is deduplicated across both pages.

• Nvd - Cve-2026-42778
  web:nvd.nist.gov

  The fix for CVE - 2026 -41409 was not applied to the 2.1.X and 2.2.X branches. Here was the original issue description: The fix for CVE -2024-52046 in Apache MINA AbstractIoBuffer.getObject () was incomplete.

  2026-06-19 02:38 UTC
• Security Update Guide - Loading - Microsoft
  web:portal.msrc.microsoft.com

  The Security Update Guide provides information on the latest Microsoft security updates, helping users understand and address potential vulnerabilities effectively.

  2026-06-19 02:38 UTC
• March 13, 2026—Hotpatch KB5084597 (OS Builds 26200.7982 and 26100.7982 ...
  web:support.microsoft.com

  This update for Windows 11, version 25H2 and 24H2 (KB5084597) incudes security improvements. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates. To view the ...

  2026-06-19 02:38 UTC
• SAP Security Patch Day - February 2026
  web:support.sap.com

  SAP security Patch Day Bulletin This post shares the information on security notes that remediate vulnerabilities discovered in SAP products. SAP strongly recommends that the customer visits the Support Portal and applies patches on priority to protect their SAP landscape. On 10th of February 2026 , SAP security patch day saw the release of 26 new security notes. Further, there was 1 update to ...

  2026-06-19 02:38 UTC
• March 2026 Patch Tuesday: Updates and Analysis | CrowdStrike
  web:www.crowdstrike.com

  Microsoft's March 2026 Patch Tuesday addresses 82 CVEs , featuring eight Critical vulnerabilities.

  2026-06-19 02:38 UTC
• May 2026 Patch Tuesday: Updates and Analysis | CrowdStrike
  web:www.crowdstrike.com

  Microsoft has released security updates for 130 vulnerabilities, including 30 critical, in its May 2026 Patch Tuesday rollout.

  2026-06-19 02:38 UTC
• Oracle Critical Patch Update Advisory - April 2026
  web:www.oracle.com

  This Critical Patch Update contains 481 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Patch Update and other Oracle Software Security Assurance activities is located at April 2026 Critical Patch Update: Executive Summary and Analysis.

  2026-06-19 02:38 UTC
• Oracle Critical Security Patch Update Advisory - May 2026
  web:www.oracle.com

  This Critical Security Patch Update contains 35 new security patches across the product families listed below. Please note that an MOS note summarizing the content of this Critical Security Patch Update and other Oracle Software Security Assurance activities is located at May 2026 Critical Security Patch Update: Executive Summary and Analysis.

  2026-06-19 02:38 UTC
• Patch Tuesday - June 2026 - Rapid7
  web:www.rapid7.com

  Microsoft is publishing 200 vulnerabilities on June 2026 Patch Tuesday, including an HTTP/2 denial of service vulnerability and an elevation of privilege vulnerability in PowerToys.

  2026-06-19 02:38 UTC
• Patch Tuesday June 2026: Security Updates & CVE Analysis
  web:zecurit.com

  Get the complete breakdown of Microsoft's June 2026 Patch Tuesday. We analyze the latest security updates and all critical CVEs .

  2026-06-19 02:38 UTC

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