Improper Verification of Source of a Communication Channel Affecting tinacms package, versions <3.9.3
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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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)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.