CVE-2026-107263 in Gutenberg
Summary
by MITRE • 10/30/2026
Incorrect Authorization vulnerability in Drupal Gutenberg allows Forceful Browsing. This issue affects Gutenberg versions: from 0.0.0 to 2.15.0, from 3.0.0 to 3.0.7.
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Analysis
by VulDB Data Team • 10/30/2026
The identified security flaw within the Drupal Gutenberg module represents a critical failure in access control mechanisms, specifically categorized under CWE-639 as Authorization Bypass Through Forceful Browsing or CWE-285 as Improper Authorization. This vulnerability arises from an insufficient validation of user permissions when handling requests related to content management and administrative functions. In secure software architecture, every action that modifies state or exposes sensitive data must be preceded by a rigorous check ensuring the initiating actor possesses the requisite privileges for that specific operation. The defect in Gutenberg versions ranging from 0.0.0 through 2.15.0 and 3.0.0 through 3.0.7 indicates that these checks were either absent or implemented incorrectly, allowing authenticated users with lower privilege levels to execute actions reserved for administrators or higher-tier roles. This type of flaw is frequently exploited via the ATT&CK technique T1078, Valid Accounts, where an attacker leverages legitimate credentials but escalates privileges by manipulating request parameters that bypass intended authorization logic.
From a technical perspective, this vulnerability likely stems from improper handling of role-based access control checks within the module's API endpoints or form submission handlers. When a user interacts with the Gutenberg editor or associated administrative interfaces, the system fails to verify whether the current session holds the necessary permissions before processing the request. Consequently, an attacker who has obtained valid credentials for a standard contributor or author account can craft specific HTTP requests that target internal APIs or configuration settings intended only for site administrators. By manipulating these requests, the attacker can perform actions such as modifying site configurations, installing modules, altering user roles, or accessing restricted content areas without triggering appropriate denial responses. The lack of server-side validation allows this forceful browsing to succeed regardless of the client-side restrictions that might be in place, highlighting a common pitfall where frontend security measures are mistakenly relied upon for backend protection.
The operational impact of this vulnerability is severe due to the potential for complete system compromise within the Drupal environment. Since Gutenberg serves as a primary interface for content creation and management, an attacker exploiting this flaw can effectively take over administrative control of the website. This leads to unauthorized modification of site structure, injection of malicious scripts through theme or module settings, and exposure of sensitive user data stored in the database. Furthermore, because Drupal is often used for high-traffic public-facing websites, gaining administrative access allows attackers to deface the site, deploy webshells, or use the server as a pivot point for further attacks against internal networks. The breadth of affected versions means that any organization running these specific releases without immediate remediation faces significant risk, particularly if they have not implemented additional compensating controls such as strict IP whitelisting for administrative paths or multi-factor authentication for privileged accounts.
Mitigation strategies must prioritize the immediate application of vendor-provided patches to upgrade the Gutenberg module to a version that resolves this authorization bypass. Organizations should verify their current installation against the specified vulnerable ranges and apply updates promptly from official Drupal channels. In scenarios where patching is not immediately feasible, administrators can implement temporary compensating controls by restricting access to administrative endpoints via web application firewall rules or reverse proxy configurations based on user roles if such granularity is supported by the infrastructure. Additionally, auditing existing user accounts for excessive privileges and enforcing principle of least privilege across all content management workflows will reduce the attack surface. Regular security assessments and penetration testing focusing on authorization logic are recommended to detect similar flaws in other modules before they can be exploited in production environments.