Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Kirby CMS (getkirby/cms, Packagist) versions before 4.9.0, and from 5.0.0 before 5.4.0, are vulnerable to server-side template injection. Sites whose option fields (checkboxes, color, multiselect, select, radio, tags, toggles) load options from untrusted queries or APIs are affected, and so is code that uses the Options package directly. An attacker needs to be an authenticated Panel user or get another authenticated user to interact with a crafted view, and can then read hidden information or alter content. Upgrade to Kirby 4.9.0, 5.4.0 or a later 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 |
|---|---|---|---|---|
| 7.6 | High | 4.0 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0033, the 27th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:25 UTC First seen by agentprime
- 31 Oct 2026, 14:25 UTC Confirmed by OSV