CVE-2025-56589 identifies a Local File Inclusion (LFI) and Server-Side Request Forgery (SSRF) vulnerability within the InsertFromHtmlString() function of the Apryse HTML2PDF SDK versions through 11.6.0. The LFI flaw allows an attacker to manipulate input parameters to trick the SDK into including and reading arbitrary local files on the server, potentially exposing sensitive configuration files, credentials, or other confidential data. The SSRF vulnerability enables an attacker to coerce the server into making arbitrary HTTP requests to internal or external network resources, which can be leveraged to access internal services not normally exposed to the internet, perform port scanning, or exploit other internal vulnerabilities. These vulnerabilities do not require any authentication or user interaction, increasing their risk profile. The CVSS 3.1 base score of 7.5 reflects the high confidentiality impact, network attack vector, and low complexity of exploitation. While no public exploits have been reported yet, the combination of LFI and SSRF in a widely used SDK for HTML to PDF conversion presents a significant threat vector, especially in environments where the SDK is integrated into web-facing applications or automated document processing workflows. The vulnerabilities stem from improper input validation and insufficient sanitization in the InsertFromHtmlString() function, which processes HTML content to generate PDFs. Attackers can exploit these flaws to disclose sensitive data or potentially escalate to system compromise depending on the server environment and additional vulnerabilities.

For European organizations, the impact of CVE-2025-56589 can be substantial. The disclosure of sensitive local files could lead to leakage of credentials, internal configurations, or personal data protected under GDPR, resulting in regulatory penalties and reputational damage. SSRF exploitation could allow attackers to pivot into internal networks, accessing critical infrastructure or confidential services that are otherwise protected by network segmentation. Organizations relying on Apryse HTML2PDF SDK in web applications, document management systems, or automated workflows are at risk of data breaches and potential lateral movement within their networks. The vulnerability could also be leveraged as a foothold for further attacks, including privilege escalation or deployment of malware. Given the SDK’s role in document processing, industries such as finance, healthcare, and government services in Europe are particularly vulnerable due to the sensitive nature of handled data. The lack of authentication and user interaction requirements means attackers can exploit this remotely and at scale, increasing the threat to large enterprises and cloud service providers hosting affected applications.

To mitigate CVE-2025-56589, European organizations should first verify if they are using Apryse HTML2PDF SDK versions up to 11.6.0 and prioritize upgrading to a patched version once available. In the absence of an immediate patch, organizations should implement strict input validation and sanitization on all HTML content passed to the InsertFromHtmlString() function to prevent malicious payloads. Network-level controls should be enforced to restrict outbound HTTP requests from servers running the SDK, limiting SSRF exploitation scope. Internal services should be segmented and protected with firewalls to prevent unauthorized access via SSRF. Monitoring and logging should be enhanced to detect unusual file access patterns or unexpected internal HTTP requests. Additionally, applying the principle of least privilege to the service account running the SDK can reduce the impact of potential exploitation. Security teams should conduct thorough code reviews and penetration testing focusing on document processing components. Finally, organizations should prepare incident response plans specific to LFI and SSRF exploitation scenarios.