Opera before 9.52 does not check the CRL override upon encountering a certificate that lacks a CRL, which has unknown impact and attack vectors. NOTE: it is not clear whether this is a vulnerability, but the vendor included it in a security section of the advisory.
Gentoo Linux Security Advisory GLSA 200811-01 - Multiple vulnerabilities have been discovered in Opera, allowing for the execution of arbitrary code. Versions below 9.62 are affected.