Concretecms: >> Concrete Cms >> 5.4.1.1 Security Vulnerabilities
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.
CVSS Score
4.8
EPSS Score
0.0
Published
2026-03-04
In Concrete CMS below version 9.4.8, a rogue administrator can add stored XSS via the Switch Language block. 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.
CVSS Score
4.8
EPSS Score
0.0
Published
2026-03-04
Concrete CMS below version 9.4.8 is subject to CSRF by a Rogue Administrator using the Anti-Spam Allowlist Group Configuration via group_id parameter which can leads to a security bypass since changes are saved prior to checking the CSRF token. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks z3rco for reporting
CVSS Score
6.8
EPSS Score
0.0
Published
2026-03-04
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.
CVSS Score
4.8
EPSS Score
0.0
Published
2026-03-04
In Concrete CMS below version 9.4.8, A stored cross-site scripting (XSS) vulnerability exists in the search block where page names and content are rendered without proper HTML encoding in search results. This allows authenticated, rogue administrators to inject malicious JavaScript through page names that executes when users search for and view those pages in search results. 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 zolpak for reporting
CVSS Score
4.8
EPSS Score
0.0
Published
2026-03-04
Concrete CMS below version 9.4.8 is vulnerable to Remote Code Execution by stored PHP object injection into the Express Entry List block via the columns parameter. An authenticated administrator can store attacker-controlled serialized data in block configuration fields that are later passed to unserialize() without class restrictions or integrity checks. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 8.9 with vector CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H. Thanks YJK ( @YJK0805 https://hackerone.com/yjk0805 ) of ZUSO ART https://zuso.ai/ for reporting.
CVSS Score
7.2
EPSS Score
0.005
Published
2026-03-04
Concrete CMS 9 to 9.4.2 and versions below 8.5.21 are vulnerable to Reflected Cross-Site Scripting (XSS) in the Conversation Messages Dashboard Page. Unsanitized input could cause theft of session cookies or tokens, defacement of web content, redirection to malicious sites, and (if victim is an admin), the execution of unauthorized actions. 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:L/VI:L/VA:N/SC:N/SI:N/SA:N. Thanks Fortbridge https://fortbridge.co.uk/ for performing a penetration test and vulnerability assessment on Concrete CMS and reporting this issue.
CVSS Score
4.8
EPSS Score
0.001
Published
2025-08-05
Concrete CMS version 9 below 9.4.0RC2 and versions below 8.5.20 are vulnerable to CSRF and XSS in the Concrete CMS Address attribute because addresses are not properly sanitized in the output when a country is not specified. Attackers are limited to individuals whom a site administrator has granted the ability to fill in an address attribute. It is possible for the attacker to glean limited information from the site but amount and type is restricted by mitigating controls and the level of access of the attacker. Limited data modification is possible. The dashboard page itself could be rendered unavailable.
The fix only sanitizes new data uploaded post update to Concrete CMS 9.4.0RC2. Existing database entries added before the update will still be “live” if there were successful exploits added under previous versions; a database search is recommended. The Concrete CMS security team gave this vulnerability CVSS v.4.0 score of 5.1 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L Thanks Myq Larson for reporting.
CVSS Score
6.5
EPSS Score
0.001
Published
2025-04-03
Concrete CMS versions 9 through 9.3.3 and versions below 8.5.19 are vulnerable to stored XSS in the calendar event addition feature because the calendar event name was not sanitized on output. Users or groups with permission to create event calendars can embed scripts, and users or groups with permission to modify event calendars can execute scripts. The Concrete CMS Security Team gave this vulnerability a CVSS v4 score of 4.6 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:N/VA:N/SC:L/SI:N/SA:N Thank you, Yusuke Uchida for reporting. CNA updated this risk rank on 20 Jan 2025 by lowering the AC based on CVSS 4.0 documentation that access privileges should not be considered for AC)
CVSS Score
5.4
EPSS Score
0.002
Published
2024-09-25
Concrete CMS versions 9.0.0 to 9.3.3 and below 8.5.19 are vulnerable to Stored XSS in the "Next&Previous Nav" block. A rogue administrator could add a malicious payload by executing it in the browsers of targeted users. The Concrete CMS Security Team gave this vulnerability a CVSS v4 score of 4.6 with vector CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N Since the "Next&Previous Nav" block output was not sufficiently sanitized, the malicious payload could be executed in the browsers of targeted users. Thanks, Chu Quoc Khanh for reporting.
CVSS Score
4.8
EPSS Score
0.005
Published
2024-09-16
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