CVE-2026-109603 in Frappe
Summary
by MITRE • 10/13/2026
Frappe Framework 15.x before 15.107.3 and 16.x before 16.17.0 relies on a vulnerable pdfkit library (CVE-2025-26240) for PDF generation, enabling server-side request forgery and local file inclusion. Authenticated attackers can supply crafted content to PDF rendering to make the server fetch internal resources or embed local server files in generated PDFs.
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Analysis
by VulDB Data Team • 10/13/2026
The Frappe Framework versions 15.x prior to 15.107.3 and version 16.x prior to 16.17.0 contain a critical security vulnerability stemming from the integration of an outdated pdfkit library, specifically identified as CVE-2025-26240. This dependency is utilized by the framework for generating PDF documents dynamically based on user-supplied content or template data. The core technical flaw lies in how the underlying pdfkit implementation processes input strings that are intended to be rendered into visual formats. Because the library does not sufficiently sanitize or restrict certain URL schemes and file path references within the HTML-to-PDF conversion pipeline, it allows for the execution of unintended server-side operations when processing maliciously crafted inputs. This architectural weakness effectively transforms a standard document generation feature into an attack vector capable of interacting with internal network resources and the local filesystem of the hosting environment.
From a technical perspective, this vulnerability facilitates two primary types of attacks: Server-Side Request Forgery (SSRF) and Local File Inclusion (LFI). When an authenticated user provides HTML content containing specific URL structures or file paths to be rendered into a PDF, the pdfkit library passes these directives directly to its underlying rendering engine. If the input contains URLs pointing to internal IP addresses or localhost endpoints, the server initiates HTTP requests on behalf of the application, bypassing standard network perimeter defenses that typically protect against external SSRF attempts. Similarly, if the input includes local file paths such as file:///etc/passwd or references to configuration files within the web root, the rendering engine reads and embeds these contents into the generated PDF document. This behavior occurs because the library fails to validate whether the requested resources are authorized for access by the application context, treating all valid syntax inputs as legitimate targets for inclusion in the output file.
The operational impact of this vulnerability is significant for organizations relying on Frappe Framework versions 15.x and 16.x that have not yet applied the specified patches. Authenticated attackers can exploit this flaw to exfiltrate sensitive data from internal services, such as database credentials stored in configuration files or proprietary business logic exposed through internal APIs. By leveraging SSRF capabilities, an attacker may also probe the internal network topology, identifying other vulnerable hosts and potentially pivoting further into the infrastructure. The ability to include local server files means that any file readable by the user account running the Frappe application can be retrieved via a generated PDF download link. This poses severe risks to data confidentiality and integrity, as sensitive information like private keys, environment variables, or source code may leak without triggering traditional intrusion detection systems designed for external threats.
This vulnerability aligns with CWE-918 Server-Side Request Forgery (SSRF) due to the unauthorized initiation of server-side network requests based on user input. It also maps closely to CWE-22 Improper Limitation of a Pathname to a Restricted Directory, commonly known as Local File Inclusion, where insufficient validation allows access to files outside the intended scope. In terms of offensive security frameworks, this exploit technique corresponds to ATT&CK T1078 Valid Accounts and T1534 Internal Spearphishing or data exfiltration via document generation mechanisms. The attack requires authentication, which limits the initial blast radius but does not mitigate the severity once access is gained through compromised credentials or session hijacking.
To remediate this issue, organizations must immediately upgrade Frappe Framework to version 15.107.3 or later for the v15 branch, and version 16.17.0 or later for the v16 branch. These releases incorporate patches that enforce stricter validation on URLs and file paths passed to the pdfkit library during PDF generation processes. Until upgrades are implemented, administrators should implement network-level controls such as firewall rules to restrict outbound connections from application servers to internal IP ranges, thereby mitigating SSRF impact. Additionally, applying input sanitization at the Frappe application layer by filtering out dangerous URL schemes like file:// or ftp:// before they reach the rendering engine can provide a temporary defensive measure. Regular security audits and dependency updates are essential to maintain resilience against evolving threats in web framework ecosystems.