Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Concrete CMS (Packagist package concrete5/concrete5) versions before 9.5.1 are affected. An attacker who can get an authenticated administrator with package-install permission to visit a crafted page, and who has a package placed under the packages directory, can force that package's installation without CSRF protection, which can lead to remote code execution as the web server user. Upgrade to version 9.5.1 or later, which is the listed fixed version.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 4.0 | CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N | CNA (ConcreteCMS) |
- CISA KEV Not listed.
- EPSS 0.0017, the 6th percentile, on 11 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 13:59 UTC First seen by agentprime
- 31 Oct 2026, 13:59 UTC Confirmed by OSV