YaCy Search Server through 1.941 contains an XML external entity injection vulnerability in SVG, FreeMind, and OpenSearch parsers that fail to disable external entity resolution. Attackers can publish malicious documents with DOCTYPE declarations containing SYSTEM entities pointing to local files, causing the crawler to exfiltrate file contents into the searchable index.

YaCy Search Server versions through 1.941 are affected by an XML External Entity (XXE) injection vulnerability. The flaw exists in three parsers: SVG, FreeMind, and OpenSearch, which fail to disable external entity resolution. Attackers can craft malicious documents with DOCTYPE declarations containing SYSTEM entities that reference local files. When the YaCy crawler processes these documents, it inadvertently exfiltrates local file contents into its searchable index, effectively leaking sensitive data. The vulnerability has been identified in specific source files including svgParser.java, mmParser.java, and opensearchdescriptionReader.java. A fix has been committed to the repository. The issue is tracked under CVE-2026-82880 and has been detailed by VulnCheck in a dedicated advisory.