CVE-2026-52773 is a medium-severity (CVSS 6.1) CWE-80 vulnerability in yeswiki/yeswiki. O3 Security confirms whether CVE-2026-52773 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Reflected XSS via Unescaped Archived-Revision `time` Parameter in `handlers/page/show.php` in YesWiki
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-52773 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 369,023 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
yeswiki/yeswikiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
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 Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | yeswiki/yeswiki | ≥ 4.1.0&&< 4.6.6 | 4.6.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for yeswiki/yeswiki. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update yeswiki/yeswiki to 4.6.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-52773 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-52773 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-52773. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-52773 in your dependencies?
O3 detects CVE-2026-52773 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.