Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-25062 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Backdropcms Backdrop Cms. Its CVSS base score is 4.4 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked in the top 23% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2025-25062 is a stored cross-site scripting (XSS) vulnerability, classified under CWE-79, affecting Backdrop CMS versions 1.28.x prior to 1.28.5 and 1.29.x prior to 1.29.3. The issue arises in the CKEditor 5 rich text editor module, where long text content is not sufficiently isolated, allowing attackers to inject specialized HTML and JavaScript. It has a CVSS v3.1 base score of 4.4 (AV:N/AC:H/PR:L/UI:R/S:C/C:L/I:L/A:N), indicating medium severity with network accessibility but high attack complexity, low privileges required, user interaction needed, and changed scope for limited confidentiality and integrity impacts.
An authenticated attacker with low privileges, such as the ability to create long text content via node or comment forms, can exploit this by embedding malicious payloads. The payload executes only when an administrator edits—rather than merely views—the affected content, potentially leading to theft of admin session data or manipulation of the admin's browser context. Exploitation requires the CKEditor 5 module to be enabled and relies on the admin's interaction.
The official Backdrop CMS security advisory (backdrop-sa-core-2025-001) recommends upgrading to Backdrop CMS 1.28.5 or 1.29.3 to mitigate the vulnerability. Additional details on the issue, including proof-of-concept exploitation, are available in third-party analyses such as those on Medium and GetAstra.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-4004
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V1.1.2V1.3.2
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation can discover missing or incorrect input neutralization through targeted web-application tests.
Input validation directly enforces neutralization of untrusted data before it reaches web output generation.
Output filtering can catch or sanitize unneutralized script content before it is served to users.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.
Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.