CVE-2026-109633 in ERPNext
Summary
by MITRE • 10/13/2026
Frappe ERPNext before 15.119.1 and 16.x before 16.32.0 contains a stored cross-site scripting vulnerability because content submitted through a public-facing booking page is stored without neutralization. Unauthenticated attackers can submit crafted content that is rendered as raw HTML in a privileged user's session, executing script to act as that user and take over the account.
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Analysis
by VulDB Data Team • 10/13/2026
The identified security flaw represents a critical Stored Cross-Site Scripting vulnerability within Frappe ERPNext versions prior to 15.119.1 and 16.x prior to 16.32.0. This weakness stems from an insufficient input validation mechanism on public-facing booking pages, where user-supplied data is persisted in the backend database without adequate sanitization or encoding of special HTML characters. Unlike reflected XSS attacks that require tricking a user into clicking a malicious link, this stored variant embeds the malicious payload directly into the application's content storage. Consequently, every time an authorized user accesses the affected page or view where this data is rendered, the browser interprets the embedded script as executable code rather than static text. This architectural flaw allows unauthenticated attackers to inject arbitrary JavaScript payloads that persist on the server side, creating a persistent threat vector against any privileged account viewing the compromised content.
From an operational perspective, the impact of this vulnerability extends far beyond simple defacement or minor data leakage. Because ERPNext is typically used for enterprise resource planning involving sensitive financial, human resources, and supply chain data, successful exploitation can lead to complete account takeover. An attacker executing scripts in the context of a privileged user session gains the ability to perform actions on behalf of that user with full administrative privileges. This includes modifying critical business records, exfiltrating confidential customer or employee information, creating unauthorized transactions, or installing further malicious modules within the ERP system. The persistence of the payload means that even if the initial attack vector is discovered and removed from public view, any previously loaded sessions may still be vulnerable until they are refreshed, and new users accessing the page will immediately trigger the script execution upon login or session initialization.
This vulnerability aligns with Common Weakness Enumeration identifier CWE-79, which classifies Improper Neutralization of Input During Web Page Generation as a standard for Cross-site Scripting attacks. The attack pattern corresponds to ATT&CK technique T1059.007, specifically Command and Scripting Interpreter via JavaScript, often utilized in the initial access or execution phases of an intrusion kill chain. Furthermore, because it involves unauthenticated input leading to privilege escalation through session hijacking or impersonation, it also touches upon CWE-642 regarding External Control of Critical State Data. The severity is amplified by the fact that ERP systems are central hubs for organizational data, making them high-value targets for persistent access and lateral movement within a network infrastructure.
Mitigation strategies must prioritize immediate patching to version 15.119.1 or later for the v15 branch, and version 16.32.0 or later for the v16 branch, as these releases contain the necessary input sanitization fixes. In environments where immediate patching is not feasible due to testing requirements, administrators should implement strict Content Security Policy headers that restrict script execution from untrusted sources and disable inline scripts if possible. Additionally, deploying a Web Application Firewall with rules capable of detecting and blocking common XSS payload signatures can provide an additional layer of defense against exploitation attempts. Regular security audits focusing on input validation across all public-facing endpoints are essential to ensure no similar vulnerabilities exist in other modules that handle user-generated content without proper encoding mechanisms.