What is the CVSS score of CVE-2026-3241?

CVE-2026-3241 has a CVSS 3.1 base score of 4.8 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

Which versions of Concrete Cms are affected by CVE-2026-3241?

Organizations using Concrete CMS below should be aware of moderate risk from CVE-2026-3241, a cross-site scripting vulnerability rated CVSS 4.8.. A patch is available.

Is there a public PoC exploit available for CVE-2026-3241?

Yes, a public proof-of-concept exploit is available for CVE-2026-3241. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-3241?

Within 30 days: Identify affected systems running Concrete CMS below and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Concrete Cms CVE-2026-3241

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-03-04 ff5b8ace-8b95-4078-9743-eac1ca5451de

GHSA-f4vq-pj32-gr4q

XSS Concrete Cms

4.8

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

4.8 MEDIUM

AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 22:05 vuln.today

PoC Detected

Mar 04, 2026 - 21:32 vuln.today

Public exploit code

Patch released

Mar 04, 2026 - 21:32 nvd

Patch available

CVE Published

Mar 04, 2026 - 03:16 nvd

MEDIUM 4.8

DescriptionCVE.org

In Concrete CMS below version 9.4.8, a stored cross-site scripting (XSS) vulnerability exists in the "Legacy Form" block. An authenticated user with permissions to create or edit forms (e.g., a rogue administrator) can inject a persistent JavaScript payload into the options of a multiple-choice question (Checkbox List, Radio Buttons, or Select Box). This payload is then executed in the browser of any user who views the page containing the form. 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 M3dium for reporting.

AnalysisAI

Stored XSS in Concrete CMS Legacy Form block below version 9.4.8 allows authenticated users with form creation permissions to inject malicious JavaScript into multiple-choice question options, which executes for all users viewing the affected form. Public exploit code exists for this vulnerability. Administrators should upgrade to version 9.4.8 or later to remediate the risk of session hijacking and data theft.

Technical ContextAI

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects Concrete Cms. In Concrete CMS below version 9.4.8, a stored cross-site scripting (XSS) vulnerability exists in the "Legacy Form" block. An authenticated user with permissions to create or edit forms (e.g., a rogue administrator) can inject a persistent JavaScript payload into the options of a multiple-choice question (Checkbox List, Radio Buttons, or Select Box). This payload is then executed in the browser of any user who views the page containing the form. The Concrete CMS security team gave this vulnerabil

RemediationAI

A vendor patch is available — apply it immediately. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.