The vulnerability is a server‑side template injection in Frappe Framework versions before 15.111.0 and 16.x before 16.21.0. User‑controlled message fields are rendered directly as templates without neutralization, which allows an attacker to inject template expressions. When evaluated in an unrestricted context, the injected expressions can execute arbitrary commands on the server, providing remote code execution capabilities.

Frappe Framework is affected, specifically any instance running a version older than 15.111.0 or any 16.x release older than 16.21.0. The affected product is identified in the platform enumeration as frappe:frappe, and the vulnerability exists across all deployments of those legacy versions.

The CVSS score for this issue is 8.7, indicating a high severity risk. EPSS data is not available, so the current probability of exploitation cannot be quantified, but the lack of detection in CISA's KEV catalog suggests it is not widely exploited yet. The attack requires authentication as a user with a common operational role, making it a credential‑based threat; once authenticated, the attacker can craft messages that trigger the malicious template evaluation. Patching remains the most effective mitigation.