CVE-2026-25498
Published: 09 February 2026
Summary
CVE-2026-25498 is a high-severity Unsafe Reflection (CWE-470) vulnerability in Craftcms Craft Cms. Its CVSS base score is 8.6 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 42.7% 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 are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Deeper analysis
CVE-2026-25498 is a remote code execution (RCE) vulnerability in Craft CMS, a platform for creating digital experiences. It affects versions 4.0.0-RC1 through 4.16.17 and 5.0.0-RC1 through 5.8.21. The issue resides in the assembleLayoutFromPost() function within src/services/Fields.php, which fails to sanitize user-supplied configuration data before passing it to Craft::createObject(). This allows injection of malicious Yii2 behavior configurations. The vulnerability is scored at CVSS 7.2 (AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H) and is linked to CWE-470 (Uncontrolled Resource Consumption). It represents an unpatched variant of the behavior injection issue fixed in CVE-2025-68455, but impacts different endpoints via a separate code path.
Authenticated administrators can exploit this vulnerability over the network with low complexity and no user interaction. By supplying crafted configuration data, they can inject arbitrary Yii2 behaviors that execute system commands on the server, potentially leading to full compromise including high confidentiality, integrity, and availability impacts.
Mitigation is available in Craft CMS version 5.8.22, which addresses the sanitization flaw. Security practitioners should upgrade affected installations immediately. Relevant resources include the fixing commit at https://github.com/craftcms/cms/commit/395c64f0b80b507be1c862a2ec942eaacb353748, the release notes at https://github.com/craftcms/cms/releases/tag/5.8.22, and the advisory at https://github.com/craftcms/cms/security/advisories/GHSA-7jx7-3846-m7w7.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-6844
Vulnerability details
Craft is a platform for creating digital experiences. In versions 4.0.0-RC1 through 4.16.17 and 5.0.0-RC1 through 5.8.21, a Remote Code Execution (RCE) vulnerability exists in Craft CMS where the assembleLayoutFromPost() function in src/services/Fields.php fails to sanitize user-supplied configuration data before…
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passing it to Craft::createObject(). This allows authenticated administrators to inject malicious Yii2 behavior configurations that execute arbitrary system commands on the server. This vulnerability represents an unpatched variant of the behavior injection vulnerability addressed in CVE-2025-68455, affecting different endpoints through a separate code path. This vulnerability is fixed in 5.8.22.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The CVE describes an RCE vulnerability in the public-facing Craft CMS web application that is directly exploitable over the network by authenticated admins via unsafe input handling in a core function, mapping to the technique for exploiting public-facing applications to achieve code execution and full system compromise.
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Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly requires validation and sanitization of all user-supplied configuration data before it is passed to Craft::createObject(), blocking the malicious Yii2 behavior injection.
Mandates prompt application of the vendor patch (5.8.22) that adds the missing sanitization in assembleLayoutFromPost().
Limits the number of users granted the administrator role that can reach the vulnerable Fields.php code path, reducing the attack surface for authenticated RCE.