jcp/xml/dsig/internal/dom/DOMCanonicalizationMethod.java in Apache Santuario XML Security for Java 1.4.x before 1.4.8 and 1.5.x before 1.5.5 allows context-dependent attackers to spoof an XML Signature by using the CanonicalizationMethod parameter to specify an arbitrary weak "canonicalization algorithm to apply to the SignedInfo part of the Signature."