CVE-2026-25498
Craftcms Craft Cms 4.0.0 – 4.16.18
Raw vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XSummary
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 Reflective Code Loading (T1620); ranked in the top 41% 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 SI-10 (Information Input Validation) and AC-3 (Access Enforcement) — 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-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 Data
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 Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Input validation directly stops externally supplied class or method names from selecting improper code via reflection.
Enforces authorization checks on the code or classes ultimately invoked, blocking unauthorized selections even if reflection is used.
Limits privileges of any code reached through unsafe reflection, reducing blast radius without stopping the selection itself.
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 avoid introducing externally controlled class selection via reflection.
Vulnerability identification processes can discover unsafe reflection during code review or scanning.
Preventing execution of unauthorized code can block exploitation of unsafe reflection at runtime.
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 standards directly forbid unsafe reflection and require whitelisting or static alternatives.
Security testing can detect and block unsafe reflection patterns before release.
Secure development lifecycle mandates input validation and design reviews that reduce unsafe reflection risks.
Application security requirements can explicitly prohibit or constrain reflection based on untrusted input.
Secure architecture principles discourage dynamic class loading from external data sources.
Access restrictions limit who can supply the malicious input but do not address the reflection flaw itself.