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

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-3240— Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form

Quick assessment

Affected
Concrete CMS Concrete CMS
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.

Concrete CMS是Concrete CMS开源的一个面向团队的开源内容管理系统。 Concrete CMS 9.4.8之前版本存在安全漏洞，该漏洞源于Legacy form元素中Question字段存在存储型跨站脚本，可能导致针对高权限账户的攻击。

AI Predicted 4.3 Difficulty: Easy EPSS 0.28% · P18

Possible ATT&CK Techniques 1 AI

T1059 · Command and Scripting Interpreter
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-3240

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy form
Source: CVE Program / CVE List V5
Vulnerability Description
In Concrete CMS below version 9.4.8, a user with permission to edit a page with element Legacy form can perform a stored XSS attack towards high-privilege accounts via the Question field. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 4.8 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Thanks minhnn42, namdi and quanlna2 from VCSLab-Viettel Cyber Security for reporting.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:L/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
Concrete CMS 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Concrete CMS是Concrete CMS开源的一个面向团队的开源内容管理系统。 Concrete CMS 9.4.8之前版本存在安全漏洞，该漏洞源于Legacy form元素中Question字段存在存储型跨站脚本，可能导致针对高权限账户的攻击。
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
Concrete CMS Concrete CMS 5 ~ 9.4.8 -

II. Public POCs for CVE-2026-3240

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-3240

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-3240 (1)

Vendor Pages for CVE-2026-3240 (1)

Same Patch Batch · Concrete CMS · 2026-03-04 · 6 CVEs total

CVE-2026-3244 Concrete CMS below version 9.4.8 is vulnerable to Stored XSS in Search Results via Page Na
CVE-2026-3452 Concrete CMS below 9.4.8 is vulnerable to stored deserialization leading to RCE in the Exp
CVE-2026-3241 Concrete CMS below version 9.4.8 is vulnerable to a stored cross-site scripting (XSS) in t
CVE-2026-3242 Concrete CMS below 9.4.8 is vulnerable to Stored XSS in the Switch Language block
CVE-2026-2994 Concrete CMS below 9.4.8 is vulnerable to CSRF by a Rogue Admin using the Anti-Spam Allowl

IV. Related Vulnerabilities

Same product: Concrete CMS
Same vendor: Concrete CMS
Same weakness: CWE-79

V. Comments for CVE-2026-3240

No comments yet

Leave a comment