CVE-2026-61741: http4s-scala-xml has an XML External Entity (XXE) processing issue
http4s-scala-xml provides EntityDecoder[F, scala.xml.Elem] instances that parse XML message bodies. These decoders used a javax.xml.parsers.SAXParserFactory obtained from SAXParserFactory.newInstance without any security configuration. With the JDK’s default settings, the parser resolves DOCTYPE declarations, external general and parameter entities, and external DTDs.
An application that uses these decoders to parse untrusted XML is vulnerable to XML External Entity (XXE) attacks. An attacker can craft a request that:
- discloses local files readable by the service process,
- performs server-side request forgery (SSRF) against internal network resources, and/or
- causes denial of service through entity expansion.
References
- github.com/advisories/GHSA-cjx3-73hr-rpw7
- github.com/http4s/http4s-scala-xml/commit/326f965a2c45fc2ddbc22545dcf551b0f719f4c8
- github.com/http4s/http4s-scala-xml/releases/tag/v0.24.1
- github.com/http4s/http4s-scala-xml/releases/tag/v1.0.0-M39
- github.com/http4s/http4s-scala-xml/security/advisories/GHSA-cjx3-73hr-rpw7
- nvd.nist.gov/vuln/detail/CVE-2026-61741
Code Behaviors & Features
Detect and mitigate CVE-2026-61741 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →