CVE-2021-40099
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP...
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP leads to remote code execution.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP leads to remote code execution.
- Record
CVE-2021-40099- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Updated
- 2026-11-02
CVE ListNo score
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP leads to remote code execution.
- Record
CVE-2021-40099- Updated
- 2026-11-02
EUVDEUVD-2021-27288No score
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP leads to remote code execution.
- Record
EUVD-2021-27288- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-25jh-rpgw-34vrNo score
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP...
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP leads to remote code execution.
- Record
GHSA-25jh-rpgw-34vr- Updated
- 2026-11-02
OSV
An issue was discovered in Concrete CMS through 8.5.5. Fetching the update json scheme over HTTP leads to remote code execution.
- Record
CVE-2021-40099- CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
Affected products
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-2021-40099 is a high vulnerability (CVSS 7.2) in Concretecms Concrete Cms, published September 24, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 2.08%, the 81st percentile. No source names a fixed version.