Open Redirect Affecting tinacms package, versions <3.14.0
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
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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Test your applications- Snyk IDSNYK-JS-TINACMS-22220119
- published5 Nov 2026
- disclosed9 Oct 2026
- creditThai Son Dinh
Introduced: 9 Oct 2026
NewCVE-2026-108261 (opens in a new tab)How to fix?
Upgrade tinacms to version 3.14.0 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 Open Redirect via the admin preview iframe URL resolution in resolvePreviewPath (and the former getExpectedPreviewOrigin). The admin preview feature loads a page in an iframe and derives the trusted postMessage origin from the preview URL supplied in the route splat parameter. An attacker can craft a link containing an off-origin URL - using forms such as a leading double slash, backslash separators, or a leading tab character - which the URL parser resolves to an external origin, causing the iframe to load a third-party page and establishing a trusted postMessage channel with that external origin, enabling cross-site content injection and data exfiltration.