Over 500 Apache Tika Servers Exposed to Critical XXE Vulnerability
A significant security vulnerability has been identified in Apache Tika, a widely used content analysis toolkit, potentially exposing over 565 internet-facing servers to malicious attacks. This flaw, designated as CVE-2025-66516, is an XML External Entity (XXE) injection vulnerability affecting tika-core versions 1.13.0 through 3.2.1, carrying a maximum CVSS severity score of 10.0.
Understanding the Vulnerability
Apache Tika is designed to process various document formats, extracting metadata and text content. The identified vulnerability allows attackers to embed a malicious XML Forms Architecture (XFA) file within a PDF document. When Tika processes this crafted file, it can lead to unauthorized access to internal resources.
Potential Impacts
Exploitation of this vulnerability can result in:
– Data Exfiltration: Attackers may access and steal sensitive information from vulnerable servers.
– Denial-of-Service (DoS) Attacks: Malicious actors can exhaust system resources, causing service disruptions.
– Server-Side Request Forgery (SSRF): The flaw can be used to make unauthorized requests to internal network resources, potentially exposing backend systems, databases, or cloud metadata endpoints that should remain protected behind firewalls.
Scope of Exposure
Security research firm Censys has identified 565 potentially vulnerable Tika Server instances accessible from the internet as of December 2025. These exposed systems span multiple countries, representing a significant attack surface for threat actors scanning for unpatched installations.
Recommended Actions
Organizations utilizing Apache Tika Server should take immediate action:
– Upgrade Tika-Core: Update to version 3.2.2 or later to address the vulnerability.
– Update Dependencies: Applications using Tika as a Maven dependency should update tika-parsers to version 1.28.6 or higher, or tika-pdf-module to version 3.2.2 or higher.
As of the time of disclosure, no proof-of-concept exploit code has been publicly released, and no active exploitation has been reported. However, given the critical severity and straightforward attack method, security teams should prioritize patching before attackers develop working exploits.
