XSS in Backdropcms Backdrop

CVE-2025-25062

An XSS issue was discovered in Backdrop CMS 1.28.x before 1.28.5 and 1.29.x before 1.29.3. It doesn't sufficiently isolate long text content when the CKEditor 5 rich text editor is used. This allows a potential attacker to craft specialized HTML and JavaScript that may be executed when an administrator attempts to edit a piece of content. This vulnerability is mitigated by the fact that an attacker must have the ability to create long text content (such as through the node or comment forms) and an administrator must edit (not view) the content that contains the malicious content. This problem only exists when using the CKEditor 5 module.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.017 (76.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2025-25062?
CVE-2025-25062 is a medium-severity vulnerability in Backdropcms Backdrop, classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2025-02-03.
How severe is CVE-2025-25062?
Medium severity. CVSS v3 base score is 4.4 out of 10.
Is CVE-2025-25062 known to be exploited?
5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.