A vulnerability in node-forge prior to version 1.4.1 causes certificate signature verification to use the issuer certificate's RSA signature scheme instead of the certificate's own declared signature algorithm. This allows a certificate labeled as signed with RSASSA-PSS to be accepted if the issuer used PKCS#1 v1.5, despite the signature actually being PKCS#1 v1.5. The flaw does not allow forging certificates but can cause incorrect acceptance or rejection of certificate chains. The issue is fixed in node-forge 1.4.1.