CVE-2026-109621 in ERPNext
Summary
by MITRE • 10/13/2026
Frappe ERPNext before 15.120.0 and 16.x before 16.23.0 contains an authorization bypass in an endpoint that honours a caller-supplied flag disabling its own permission enforcement. Authenticated attackers can set this flag when calling the endpoint to skip permission checks and read party records beyond their permitted role.
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability identified in Frappe ERPNext versions prior to 15.120.0 and 16.x prior to 16.23.0 represents a critical authorization bypass within the application's core framework logic. This flaw stems from an insecure design pattern where specific API endpoints are configured to accept caller-supplied flags that directly influence permission enforcement mechanisms. Specifically, these endpoints honor a parameter intended for internal testing or administrative override purposes but fail to validate whether such overrides should be permitted based on the current user’s role and privileges. By allowing authenticated users to inject this flag into their requests, attackers can effectively disable the server-side security checks designed to restrict access to sensitive data structures.
From a technical perspective, the root cause lies in the improper validation of input parameters that control execution flow regarding authorization policies. The application framework likely utilizes a mechanism where permission checks are conditionally skipped if certain flags are present, assuming these flags originate only from trusted internal processes or administrators with explicit rights to perform such actions. However, because this flag is exposed via public-facing endpoints and lacks sufficient server-side verification of the caller’s authority to request it, any authenticated user can manipulate the endpoint's behavior. This constitutes a classic case of insecure direct object references combined with broken access control, where the system trusts client-supplied data regarding its own security posture without adequate validation against the principle of least privilege.
The operational impact of this vulnerability is severe, as it allows authenticated attackers to bypass role-based access controls and read party records that they are not authorized to view. In an ERPNext environment, party records typically contain sensitive business information including customer details, supplier contracts, pricing agreements, and potentially personally identifiable information depending on the configuration. An attacker exploiting this flaw could exfiltrate confidential corporate data, leading to significant confidentiality breaches. Furthermore, since the vulnerability affects multiple major versions of the software, it poses a widespread risk to organizations relying on ERPNext for their enterprise resource planning operations, potentially facilitating further attacks such as social engineering or competitive intelligence gathering based on stolen party data.
This issue aligns with CWE-284 Improper Access Control and CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes, as the attacker modifies an object attribute (the permission flag) to alter security behavior. In terms of MITRE ATT&CK mapping, this vulnerability facilitates Initial Access or Defense Evasion techniques by allowing unauthorized data access through manipulation of API parameters. To mitigate this risk, organizations must immediately upgrade Frappe ERPNext to version 15.120.0 or later for the v15 branch and version 16.23.0 or later for the v16 branch. Additionally, developers should review all endpoints that accept flags influencing security logic to ensure they are strictly validated against user roles before being processed. Implementing strict input validation and ensuring that administrative overrides cannot be triggered by standard authenticated users is essential to preventing similar authorization bypasses in future updates.