CVE-2026-52774
MediumPublic exploitYesWiki Vulnerable to Reflected XSS via Unescaped id Parameter in Bazar Widget HTML Attributes
Published Jul 9, 2026 · Updated Sep 10, 2026 · Also known as GHSA-r5xw-gcgw-hwp5
Key Facts
Routine patching- CVE-2026-52774 is a medium-severity vulnerability (CVSS 6.1 v3.1) affecting yeswiki/yeswiki (composer), yeswiki.
- It is not listed in any known-exploited vulnerabilities catalog. Public exploit code is available.
- EPSS estimates a 0.7% probability of exploitation in the next 30 days.
- Fixed versions are available, including yeswiki/yeswiki 4.6.6.
- Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
CVSS v3.1
6.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS (30-day exploit likelihood)
0.7%
Higher than 50.4% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
Available
Proof-of-concept or weaponized module
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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.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| yeswiki/yeswikicomposer | See advisory | 4.6.6 |
| yeswiki | >= < 4.6.6 | n/a |
Patched Releases
yeswiki/yeswiki
4.6.6
Timeline
Publicly disclosed
Jul 9, 2026
Last updated
Sep 10, 2026
Weakness Type
- CWE-80 Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52774.json
- advisoryhttps://github.com/YesWiki/yeswiki/commit/1aa2710c7505630b858f2142a65f9441bfaba2b2
- advisoryhttps://github.com/YesWiki/yeswiki/security/advisories/GHSA-r5xw-gcgw-hwp5
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-52774
FAQ
Common Questions.
YesWiki is a wiki system written in PHP.
Affected: yeswiki/yeswiki (composer); yeswiki versions >= < 4.6.6. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including yeswiki/yeswiki 4.6.6.
Brandefense priority: routine patching, as no exploitation is known and its severity is moderate or low.
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