An issue was discovered in Backdrop CMS 1.13.x before 1.13.5 and 1.14.x before 1.14.2. It doesn't sufficiently filter output when displaying certain block descriptions created by administrators. An attacker could potentially craft a specialized description, then have an administrator execute scripting when configuring a layout, aka XSS. This issue is mitigated by the fact that the attacker would be required to have the permission to create custom blocks, which is typically an administrative task.
Conclusion & alert: CVE-2019-19901 is rated Low Risk (39.2/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 0.35%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-04-13 | 0.35% | 0.35% | -0.01% |
| 2 | 2025-03-17 | 0.05% | 0.35% | +0.30% |
| 3 | 2023-03-07 | — | 0.05% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 4.8 | 3.1 | MEDIUM |
|
1.7 | 2.7 | [email protected] |
| 3.5 | 2.0 | LOW |
|
6.8 | 2.9 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| backdropcms | backdrop_cms | >= 1.13.0, < 1.13.5 | cpe:2.3:a:backdropcms:backdrop_cms:*:*:*:*:*:*:*:* |
| backdropcms | backdrop_cms | >= 1.14.0, < 1.14.2 | cpe:2.3:a:backdropcms:backdrop_cms:*:*:*:*:*:*:*:* |
| URL | Tags |
|---|---|
| https://backdropcms.org/security/backdrop-sa-core-2019-013 | Vendor Advisory |