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TI-2026-02802 Aliases CVE-2026-3241GHSA-f4vq-pj32-gr4q

Concrete CMS below version 9.4.8 is vulnerable to a stored cross-site scripting (XSS) in the "Legacy Form" block.

Priority LOW 22CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
High
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00238 14th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed concrete5/concrete5 (Packagist): 9.4.8

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
—concrete5/concrete5 (Packagist)before 9.4.89.4.8Patch availableGHSA-f4vq-pj32-gr4q
  • concrete5/concrete5 (Packagist) Vendor— Affected before 9.4.8 Fixed in 9.4.8 Patch available GHSA-f4vq-pj32-gr4q

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:*before 9.4.8VulnerableConcrete CMS
  • cpe:2.3:a:concretecms:concrete_cms:*:*:*:*:*:*:*:* Versions before 9.4.8 Vulnerable ·Concrete CMS

Remediation

  • Fix · GHSA-f4vq-pj32-gr4q concrete5/concrete5 (Packagist) Fixed in 9.4.8 Advisory →

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    Concrete CMS 9.4.8

    6 records Highest priority Priority MEDIUM 1 MEDIUM, 5 LOW

    Other records, highest priority first

    • TI-2026-02973 Concrete CMS below 9.4.8 is vulnerable to stored deserialization leading to RCE in the Express Entry List block.Priority MEDIUM 42
    • TI-2026-02803 Concrete CMS below 9.4.8 is vulnerable to Stored XSS in the Switch Language blockPriority LOW 22
    • TI-2026-02801 Concrete CMS below 9.4.8 is vulnerable to Stored XSS via Legacy formPriority LOW 22
    Show all 6 records →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-3241
  2. 2026-10-03 Alias added: GHSA-f4vq-pj32-gr4q

References

Exploit 1

Patch 1

Advisory 1

Other 1

  • TI-2026-23602 ConcreteCMS v9.4.7 contains a Denial of Service (DoS) vulnerability in the File Manager… CVSS 3.1MEDIUM 6.5
  • TI-2023-23992 A Cross Site Scripting (XSS) vulnerability in Concrete CMS from versions 9.2.0 to 9.2.2… CVSS 3.1MEDIUM 5.4
  • TI-2023-26495 Concrete CMS before 8.5.13 and 9.x before 9.2.2 allows unauthorized access because… CVSS 3.1CRITICAL 9.8
  • TI-2026-14907 Missing authorization in Concrete CMS CVSS 4.0HIGH 8.7
  • TI-2022-06200 Cleartext transmission of sensitive information in https://github.com/concrete5/concrete5 CVSS 3.1CRITICAL 9.8
  • TI-2021-17294 An issue was discovered in Concrete CMS through 8.5.5. CVSS 3.1CRITICAL 9.8
See all 197 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences