CVE-2026-61457 getgrav CVE debrief

Who should care

Administrators and users of the Grav API plugin, especially those with api.media.write permission, should assess exposure and take action to prevent exploitation. This includes reviewing plugin versions, restricting file uploads, and monitoring for suspicious activity. Additionally, security teams and vulnerability management teams should verify plugin configurations and user permissions, and conduct regular security audits and vulnerability assessments.

Why it matters

CVE-2026-61457 is a medium-severity vulnerability in the Grav API plugin that allows remote code execution via a file upload extension bypass. Users with api.media.write permission can upload malicious files, potentially leading to elevation of privileges and execution of arbitrary code. Defenders should verify plugin versions, restrict file uploads, and monitor for suspicious activity.

• Remote code execution possible via file upload extension bypass
• Elevation of privileges for users with api.media.write permission
• Potential for malicious file uploads and execution
• Verification of Grav API plugin version and configuration required

Technical summary

The Grav API plugin (getgrav/grav-plugin-api) before 1.0.3 contains a file upload extension bypass in the API media controller. This allows a user with api.media.write permission to upload a file with a double extension, such as shell.php.jpg, which can be executed as PHP by the web server, resulting in remote code execution. The vulnerability arises from HandlesMediaUploads::validateFileExtension() inspecting only the final file extension via pathinfo($filename, PATHINFO_EXTENSION). Affected users should review and update plugin versions, restrict file uploads, and monitor for suspicious activity.

Defensive priority

Medium priority for Grav API plugin users

Recommended defensive actions

• Review and update Grav API plugin versions to 1.0.3 or later
• Restrict file uploads to only allow specific, safe extensions
• Monitor for suspicious file uploads and API usage
• Implement additional security measures, such as web application firewalls
• Verify plugin configurations and user permissions
• Conduct regular security audits and vulnerability assessments
• Review and update incident response plans

Evidence notes

The CVE record and NVD entry provide details on the file upload extension bypass vulnerability in the Grav API plugin. However, the corpus lacks specific information on affected versions, exploitation, and remediation.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.