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CVE-2026-52766 — YesWiki is a wiki system written in PHP.

Key facts

CVE-2026-52766 is a Critical (9.1) vulnerability: YesWiki is a wiki system written in PHP.. This entry ships a detection-only PoC and a Docker test lab.

CVE CVE-2026-52766
Severity Critical (9.1)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-52766/

Details

English | 한국어

Description

YesWiki is a wiki system written in PHP. Prior to version 4.6.6, the {{erasespamedcomments}} wiki action (actions/EraseSpamedCommentsAction.php) accepts a suppr[] array from POST and deletes every wiki page whose tag appears in that array, with no authorization check anywhere in the action body or in the page-deletion path it invokes. Combined with YesWiki's allow-by-default action ACL model, any user who has page write access, which is the default for everyone (default_write_acl='*') on a fresh install can permanently delete arbitrary wiki pages, including the front page, admin pages, and pages owned by other users. This issue has been patched in version 4.6.6.

Vulnerability Details

Property Value
CVE ID CVE-2026-52766
CVSS Score 9.1

Proof of Concept

Download

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-52766/poc.py

Usage

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start

# Clone and navigate to CVE directory
cd CVE-2026-52766

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints

Application URL Status
Vulnerable App http://localhost:8080 Shows vulnerability
Patched App http://localhost:8081 Demonstrates fix

Directory Structure

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References

  • https://github.com/YesWiki/yeswiki/commit/ed5b548a705c8091ba0282aaaba73ddda976abef
  • https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6
  • https://github.com/YesWiki/yeswiki/security/advisories/GHSA-6x7x-gcmf-7r8x

Generated by PoC Generator on 2026-09-05T11:04:43.788416485

Frequently asked questions

What is CVE-2026-52766?

CVE-2026-52766 is a Critical (9.1) vulnerability: YesWiki is a wiki system written in PHP.. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-52766?

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-52766?

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.


For authorized security testing and research only. See the full source and NVD record.