CVE-2026-27621
Fix: TypiCMS/Core@d480a0bCVE-2026-27621 is a Cross-site Scripting (XSS) vulnerability in typicms/core. O3 Security confirms whether CVE-2026-27621 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
TypiCMS Core has Stored Cross-Site Scripting (XSS) via SVG File Upload
Real-World Exposure
typicms/core🐘typicms/core🐘typicms/core🐘typicms/core🐘typicms/coreReal-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
TypiCMS is a multilingual content management system based on the Laravel framework. A Stored Cross-Site Scripting (XSS) vulnerability exists in the file upload module of TypiCMS prior to version 16.1.7. The application allows users with file upload permissions to upload SVG files. While there is a MIME type validation, the content of the SVG file is not sanitized. An attacker can upload a specially crafted SVG file containing malicious JavaScript code. When another user (such as an administrator) views or accesses this file through the application, the script executes in their browser, leading to a compromise of that user's session. The issue is exacerbated by a bug in the SVG parsing logic, which can cause a 500 error if the uploaded SVG does not contain a viewBox attribute. However, this does not mitigate the XSS vulnerability, as an attacker can easily include a valid viewBox attribute in their malicious payload. Version 16.1.7 of TypiCMS Core fixes the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | typicms/core | ≥ 16.0.0&&< 16.1.7 | 16.1.7 |
| 🐘Packagist | typicms/core | ≥ 15.0.0&&< 15.0.29 | 15.0.29 |
| 🐘Packagist | typicms/core | ≥ 14.0.0&&< 14.0.27 | 14.0.27 |
| 🐘Packagist | typicms/core | ≥ 13.0.0&&< 13.0.9 | 13.0.9 |
| 🐘Packagist | typicms/core | all versions | 12.0.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for typicms/core. 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 typicms/core to 16.1.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-27621 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-2026-27621 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-2026-27621. 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-2026-27621 in your dependencies?
O3 detects CVE-2026-27621 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.