Description
ApostropheCMS is an open-source Node.js content management system. Prior to 4.34.0, the color field accepts trailing content after a valid rgb() or hsl() prefix because its TinyColor validation does not require the entire value to match a color. An authenticated user with edit rights can store arbitrary HTML after a valid color prefix. When the stored value is rendered, the payload executes, resulting in stored XSS. This issue is fixed in version 4.34.0.
References5
- github.com/apostrophecms/apostrophe/commit/06e4b377f3c360f9e89c…
- github.com/apostrophecms/apostrophe/commit/40b989b1a9dd23d30029…
- github.com/apostrophecms/apostrophe/releases/tag/[email protected]…
- github.com/apostrophecms/apostrophe/security/advisories/GHSA-vm…
- github.com/apostrophecms/apostrophe/security/advisories/GHSA-vm…
Metrics
- CVSS 3.1
-
5.4
MEDIUM
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N - EPSS — exploit probability
- 0% percentile: 23 · as of 9 November 2026
- CWE
- CWE-79
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.