CVE-2026-55793
Craft CMS: Stored XSS via Structure entry title in table view
Blast Radius
craftcms/cmsReal-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
Craft CMS is a content management system (CMS). In versions 5.0.0-RC1 through 5.9.22, an author-level control panel user can store a malicious JavaScript payload in an entry title. When an admin, or any control panel user with saveEntries for the same Structure section, drags another entry under the poisoned entry in table view, the payload executes in the victim’s session. The issue is exploitable because the title is escaped into data-title by the server, decoded again by the browser, read with jQuery .data('title'), and then concatenated into a new HTML string without attribute escaping. To exploit, an attacker must have an existing control panel account (Author role minimum), the victim must perform a drag operation (not just visit the page), and the victim’s session needs to be elevated at trigger time. This issue has been fixed in version 5.9.23.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | craftcms/cms | ≥ 5.0.0-RC1&&< 5.9.53 | 5.9.53 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for craftcms/cms. 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 craftcms/cms to 5.9.53 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-55793 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-2026-55793 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-2026-55793. 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-2026-55793 in your dependencies?
O3 detects CVE-2026-55793 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.