CVE intelligence and bounded remediation

CVE-2026-27621 — TypiCMS is a multilingual content management system based on the Laravel framework

Medium CVSS 6.8

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.

Severity
Medium
CVSS
6.8 (4.0)
Published
2026-02-25
CISA KEV
Not currently listed
Ecosystem
javascript/npm
Weaknesses
CWE-79

Affected products

  • typicms / typicms

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

The detailed catalog view below loads this exact record, its source evidence, and the full seven-phase agentic change plan.