CVE-2021-28145
Concrete CMS Cross-site Scripting via Survey Blocks
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct XSS attacks via a crafted survey block. This requires at least Editor privileges.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct XSS attacks via a crafted survey block. This requires at least Editor privileges.
- Record
CVE-2021-28145- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - CVSS 2.0
- 3.5 Low
AV:N/AC:M/Au:S/C:N/I:P/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
CVE List No score
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct XSS attacks via a crafted survey block. This requires at least Editor privileges.
- Record
CVE-2021-28145- Updated
- 2026-11-02
EUVDEUVD-2022-2902 No score
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct XSS attacks via a crafted survey block. This requires at least Editor privileges.
- Record
EUVD-2022-2902- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-7388-7vq2-m4f4
Concrete CMS Cross-site Scripting via Survey Blocks
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct Cross-site Scripting (XSS) attacks via a crafted survey block. This requires at least Editor privileges.
- Record
GHSA-7388-7vq2-m4f4- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct XSS attacks via a crafted survey block. This requires at least Editor privileges.
- Record
CVE-2021-28145- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
OSVGHSA-7388-7vq2-m4f4
Concrete CMS Cross-site Scripting via Survey Blocks
Concrete CMS (formerly concrete5) before 8.5.5 allows remote authenticated users to conduct Cross-site Scripting (XSS) attacks via a crafted survey block. This requires at least Editor privileges.
- Record
GHSA-7388-7vq2-m4f4- CVSS 3.1
- 5.4 Medium
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
concrete5/concrete5Packagist |
before 8.5.5 | 8.5.5 |
concrete5/concrete5Packagist |
before 8.5.5, plus listed versions 8.08.0.18.0.28.0.38.1.0 Show 21 moreShow less8.2.08.2.0RC28.2.18.3.08.3.18.3.28.4.08.4.0RC38.4.0RC48.4.18.4.28.4.38.4.48.4.58.5.08.5.0RC18.5.0RC28.5.18.5.28.5.38.5.4 |
8.5.5 |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-28145 is a medium vulnerability (CVSS 5.4) in Concretecms Concrete Cms, published March 18, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.86%, the 58th percentile. Fixed in concrete5/concrete5 8.5.5.