Opera before 12.10 does not properly handle incorrect size data in a WebP image, which allows remote attackers to obtain potentially sensitive information from process memory by using a crafted image as the fill pattern for a canvas.

Opera before 12.10 follows Internet shortcuts that are referenced by a (1) IMG element or (2) other inline element, which makes it easier for remote attackers to conduct phishing attacks via a crafted web site, as exploited in the wild in November 2012.

Heap-based buffer overflow in Opera before 12.11 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a long HTTP response.

In the WebRTC component in Opera 51.0.2830.55, after visiting a web site that attempts to gather complete client information (such as https://ip.voidsec.com), the browser can disclose a private IP address in a STUN request.

Opera before 57.0.3098.106 is vulnerable to a DLL Search Order hijacking attack where an attacker can send a ZIP archive composed of an HTML page along with a malicious DLL to the target. Once the document is opened, it may allow the attacker to take full control of the system from any location within the system. The issue lies in the loading of the shcore.dll and dcomp.dll files: these files are being searched for by the program in the same system-wide directory where the HTML file is executed.