CVE-2026-109315 in Grav
Summary
by MITRE • 10/12/2026
Grav from 2.0.22 before 2.1.7 contains an information disclosure vulnerability that allows page editors to read the Clockwork debugger token because the sandbox redaction list omits system.debugger.token. Attackers can render the token through editor-authored Twig and supply it as X-Clockwork-Auth to read profiler records with configuration, request metadata, and database queries.
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Analysis
by VulDB Data Team • 10/12/2026
The vulnerability identified in Grav versions prior to 2.1.7 represents a critical information disclosure flaw rooted in an insufficiently configured security sandbox within the application's Twig templating engine. Grav is a popular flat-file CMS that utilizes Twig for its template rendering, and it employs a sandbox mode to restrict access to potentially dangerous methods or properties when content is authored by users with editor-level privileges rather than administrators. The core technical flaw lies in the oversight of the redaction list used during this sanitization process. Specifically, while many sensitive system objects are properly restricted, the configuration failed to include system.debugger.token within the exclusion list. This omission allows page editors, who typically have limited permissions intended for content creation and modification, to bypass security controls by accessing internal debugging artifacts that should remain hidden from non-administrative users.
From a technical perspective, this vulnerability enables an attacker with editor-level access to extract sensitive operational data through crafted Twig templates. By leveraging the lack of redaction on the debugger token property, an authenticated user can render and retrieve the Clockwork authentication token directly within their authored content or via specific template injections. Once obtained, this token serves as a valid credential for interacting with the Clockwork debugging interface. The attacker can then supply this token in the X-Clockwork-Auth HTTP header to access detailed profiler records. These records contain highly sensitive information including application configuration details, complete request metadata such as headers and cookies, and potentially unencrypted database queries that may expose user data or internal system logic. This effectively elevates a low-privilege account into one capable of performing deep reconnaissance on the underlying infrastructure and application state without requiring administrative credentials.
The operational impact of this vulnerability is significant due to its potential for facilitating further attacks through information gathering. The exposure of configuration files can reveal database connection strings, API keys, or other secrets embedded in the system settings. Access to request metadata allows attackers to analyze session management practices, identify valid user tokens, and understand traffic patterns that could aid in crafting more targeted phishing or injection attacks. Furthermore, the visibility into database queries may expose schema structures and sensitive data stored within the flat files or associated databases, leading to a comprehensive compromise of confidentiality. This aligns with CWE-200, which classifies this as an Information Exposure vulnerability where security-sensitive information is disclosed without explicit access control enforcement. Additionally, from a threat modeling perspective using MITRE ATT&CK frameworks, this behavior corresponds to techniques such as T1592 (Gather Victim Host Information) and T1537 (Transfer Data to Cloud Account), as the attacker extracts data that can be used for lateral movement or exfiltration in subsequent stages of an attack chain.
To mitigate this vulnerability, organizations running Grav CMS must immediately upgrade to version 2.1.7 or later, where the sandbox redaction list has been corrected to properly exclude system.debugger.token from accessible properties by non-administrative users. In environments where upgrading is not immediately feasible, administrators should consider restricting editor-level permissions further until the patch can be applied. It is also advisable to audit existing user roles and ensure that only trusted individuals have access to content editing features. Regular security audits of third-party components and their configuration settings are essential to prevent similar oversights in sandboxing mechanisms. Monitoring logs for unusual requests containing X-Clockwork-Auth headers can also help detect exploitation attempts, although prevention through patching remains the most effective defense strategy against this specific information disclosure flaw.