Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-55660— TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover

Quick assessment

Affected
tinacms tinacms
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Tina TinaCMS是Tina组织开源的一款完全开源的无头内容管理系统，支持 Markdown 和可视化编辑，通过 GraphQL API 让开发者像查询数据库一样查询 Markdown 内容。 Tina tinacms存在安全漏洞，该漏洞源于跨域postMessage处理程序未验证事件来源和目标以及富文本URL清理不足，导致存储型跨站脚本和会话接管。

AI Predicted 8.8 Difficulty: Easy EPSS 0.28% · P18

Affected Version Matrix 2

VendorProduct Version RangeStatus
tinacms @tinacms/app < 2.5.6 affected
tinacms tinacms < 3.9.3 affected
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-55660

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
TinaCMS: Cross-origin postMessage handlers and rich-text URL-sanitization bypass enable stored XSS and session takeover
Source: CVE Program / CVE List V5
Vulnerability Description
Tina is a headless content management system. In versions prior to @tinacms/app 2.5.6 and tinacms 3.9.3, cross-origin postMessage handlers and a rich-text URL-sanitization bypass enable stored XSS and session takeover. The library registers window message listeners — the useTina overlay handler, the OAuth authentication popup handler, and the admin↔preview iframe GraphQL reducer — that act on event.data without verifying event.origin or event.source and post messages using non-specific target origins, while insufficient URL sanitization in rich-text content allows malicious URLs to persist and execute. A page the victim visits (or a window in an opener/iframe relationship with a Tina admin) can forge messages to drive the editor, inject preview content, or observe/forge the OAuth popup channel to take over an authenticated editing session. This issue has been fixed in versions @tinacms/app 2.5.6 and tinacms 3.9.3.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Source: CVE Program / CVE List V5
Vulnerability Type
在Web页面生成时对输入的转义处理不恰当(跨站脚本)
Source: CVE Program / CVE List V5
Vulnerability Title
Tina tinacms 输入验证错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Tina TinaCMS是Tina组织开源的一款完全开源的无头内容管理系统，支持 Markdown 和可视化编辑，通过 GraphQL API 让开发者像查询数据库一样查询 Markdown 内容。 Tina tinacms存在安全漏洞，该漏洞源于跨域postMessage处理程序未验证事件来源和目标以及富文本URL清理不足，导致存储型跨站脚本和会话接管。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
tinacms tinacms < 3.9.3 -
tinacms @tinacms/app < 2.5.6 -

II. Public POCs for CVE-2026-55660

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-55660

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-55660 (1)

Vendor Advisories for CVE-2026-55660 (1)

Same Patch Batch · tinacms · 2026-07-01 · 3 CVEs total

CVE-2026-54074 7.8 HIGH @tinacms/cli: Remote Code Execution via Forestry migration — unsanitised __TINA_INTERNAL__
CVE-2026-55661 TinaCMS rich-text (slatejson) rendering does not sanitize link/image URLs, allowing stored

IV. Related Vulnerabilities

Same product: tinacms
Same vendor: tinacms
Same weakness: CWE-79

V. Comments for CVE-2026-55660

No comments yet

Leave a comment