libexpat before 2.8.0 uses insufficient entropy, and thus hash flooding can occur via a crafted XML document.
References
- http://www.openwall.com/lists/oss-security/2026/04/26/1
- https://blog.hartwork.org/posts/expat-2-8-0-released/
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://github.com/libexpat/libexpat/issues/47
- https://github.com/libexpat/libexpat/pull/1183
- https://www.openwall.com/lists/oss-security/2026/04/26/1