---
id: CVE-2026-52771
title: YesWiki is a wiki system written in PHP
summary: >-
  YesWiki is a wiki system written in PHP. From version 4.2.0 to before version
  4.6.6, ApiController::deletePage() interpolates a page tag retrieved from the
  database into a DELETE FROM …_links WHERE to_tag = '$tag' query without
  escaping.…
severity: high
cvss: 8.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L'
cwe:
  - CWE-89
vendor: YesWiki
product: yeswiki
affected:
  - 'yeswiki >= 4.2.0, < 4.6.6'
patched:
  - yeswiki/yeswiki 4.6.6
published: '2026-09-05'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:05:26.920'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-52771'
references:
  - url: >-
      https://github.com/YesWiki/yeswiki/commit/23d3cc124613b9428ab963b31807c08879a9c631
    label: security-advisories@github.com
  - url: 'https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6'
    label: security-advisories@github.com
  - url: 'https://github.com/YesWiki/yeswiki/security/advisories/GHSA-8f2v-2qhj-gfwg'
    label: security-advisories@github.com
  - url: 'https://github.com/advisories/GHSA-8f2v-2qhj-gfwg'
tags:
  - nvd
  - cve.org
  - ghsa
  - composer
epss: 0.00512
epssPercentile: 0.41193
aliases:
  - GHSA-8f2v-2qhj-gfwg
ecosystem: composer
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-08T16:41:16.858942Z'
ingestedAt: '2026-07-09T21:52:34.682Z'
---

## Overview

YesWiki is a wiki system written in PHP. From version 4.2.0 to before version 4.6.6, ApiController::deletePage() interpolates a page tag retrieved from the database into a DELETE FROM …_links WHERE to_tag = '$tag' query without escaping. The page tag is attacker-controlled — the POST /api/pages/{tag} API accepts arbitrary URL-encoded values, including single quotes, and stores them. A low-privilege authenticated user can therefore create a page whose tag is a SQL fragment, make the page non-orphaned via the standard {{include page="…"}} link mechanism, and then invoke the delete endpoint to execute arbitrary SQL inside the wiki database - including time-based blind data exfiltration from any table. This issue has been patched in version 4.6.6.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-52771)

Affected packages:

- `yeswiki/yeswiki >= 4.2.0, < 4.6.6`

Patched in:

- `yeswiki/yeswiki 4.6.6`

Source: https://github.com/advisories/GHSA-8f2v-2qhj-gfwg