Apache Tika is an open-source, highly-used framework for extracting text, metadata, and structured content from a wide array of file formats. It is commonly used within enterprise workflows including compliance systems, document ingestion pipelines, Elasticsearch and Apache Solr indexing, search engines, and automated content scanning processes. Because of its broad use, any severe issue within the platform has wide-ranging consequences.
According to the advisory for the project, the vulnerability exists in several modules, such as tika-core, tika-parsers, and the tika-pdf-module, on different versions, from 1.13 to 3.2.1. The issue allows an attacker to embed malicious XFA -- a technology that enables XML Forms Architecture -- content inside PDF files. Upon processing, Tika may execute unwanted calls to embedded external XML entities, thus providing a way to fetch restricted files or gain access to internal resources.
The advisory points out that CVE-2025-66516 concerns an issue that was previously disclosed as CVE-2025-54988, but its scope is considerably broader. Whereas the initial advisory indicated the bug was limited to the PDF parser, subsequent analysis indicated that the root cause of the bug-and therefore the fix-represented in tika-core, not solely its parser component. Consequently, any organization that has patched only the parser without updating tika-core to version 3.2.2 or newer remains vulnerable.
Researchers also provided some clarification to note that earlier 1.x releases contained the vulnerable PDF parser in the tika-parsers module, so the number of affected systems is higher than initial reporting indicated.
XXE vulnerabilities arise when software processes XML input without required restrictions, permitting an attacker to use external entities (these are references that can point to either remote URLs or local files). Successfully exploited, this can lead to unauthorized access, SSRF, disclosure of confidential files, or even an escalation of this attack chain into broader compromise.
Project maintainers strongly recommend immediate updates for all deployments. As no temporary configuration workaround has been confirmed, one can only install patched versions.
