Improper Verification of Source of a Communication Channel Affecting tinacms package, versions <3.9.3
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Start learning- Snyk IDSNYK-JS-TINACMS-17420390
- published23 Jun 2026
- disclosed19 Jun 2026
- creditkulesy
Introduced: 19 Jun 2026
NewCVE-2026-55660 (opens in a new tab)Common Vulnerabilities and Exposures (CVE) are common identifiers for publicly known security vulnerabilities
Common Weakness Enumeration (CWE) is a category system for software weaknesses
Common Weakness Enumeration (CWE) is a category system for software weaknesses
How to fix?
Upgrade tinacms to version 3.9.3 or higher.
Overview
tinacms is a headless content management system with support for Markdown, MDX, JSON, YAML, and more.
Affected versions of this package are vulnerable to Improper Verification of Source of a Communication Channel via improper validation of cross-origin messages in the window message listeners. An attacker can hijack authenticated editing sessions by sending crafted postMessage events from a malicious origin.