CVE-2026-52773
MediumPublic exploitYesWiki Vulnerable to Reflected XSS via Unescaped Archived-Revision time Parameter in handlers/page/show.php
Published Jul 9, 2026 · Updated Sep 10, 2026 · Also known as GHSA-35f3-pg38-486f
Key Facts
Routine patching- CVE-2026-52773 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 0.6% 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)
0.6%
Higher than 47.1% 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
Get the full CVE-2026-52773 brief as a PDF
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Description
YesWiki is a wiki system written in PHP. From version 4.1.0 to before version 4.6.6, YesWiki's archived-revision view reflects the time GET parameter into a hidden HTML input in handlers/page/show.php without escaping. Because MySQL coerces malformed DATETIME strings, an attacker can append HTML or JavaScript to a valid archived revision timestamp, still load that archived revision, and execute arbitrary JavaScript in the victim's browser. The vulnerable form is only rendered when the victim can both read and edit the target page. In restricted deployments this requires a victim with read and write access to that page. On a default doryphore 4.6.5 install, public pages such as PagePrincipale were editable anonymously during validation, so the issue can also affect unauthenticated visitors in that configuration. This issue has been patched in version 4.6.6.
Affected Products
2 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| yeswiki/yeswikicomposer | >= 4.1.0 | 4.6.6 |
| yeswiki | >= >= 4.1.0, < 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-2026-52773.json
- advisoryhttps://github.com/YesWiki/yeswiki/commit/35ad9c2bb6cd338198b37c1f745e24bc302a3560
- advisoryhttps://github.com/YesWiki/yeswiki/security/advisories/GHSA-35f3-pg38-486f
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-52773
FAQ
Common Questions.
YesWiki is a wiki system written in PHP.
Affected: yeswiki/yeswiki (composer) versions >= 4.1.0; yeswiki versions >= >= 4.1.0, < 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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