Specially crafted WebP images can be used to disclose random chunks of memory – Opera Security Advisories

WebP images may be used as fill patterns in a HTML5 Canvas, and the values of each pixel in the image can then be intentionally read using scripts. Specially crafted WebP images may specify the wrong size for certain parts of their data, which causes Opera to read data from the wrong positions in...

Certificate revocation service failure may cause Opera to show an unverified site as secure – Opera Security Advisories

When accessing secure websites, Opera checks with a number of services to check if the website’s security certificate has been revoked. Normally, if Opera cannot check revocation status, it will not present the site as secure. In some cases, a failure in one of these services can cause Opera not ...

Internet shortcuts used for phishing in elements – Opera Security Advisories

Websites may occasionally want to display image content from untrusted sources. A phishing attack may be carried out by the untrusted source, by displaying malicious instructions on the image, or by navigating the containing page to a similar looking document on another server. Since some image...

Certain characters in HTML can incorrectly be ignored, which can facilitate XSS attacks – Opera Security Advisories

Sites that allow content to be provided by untrusted users, such as forums and blogging sites, typically sanitize the untrusted content to ensure that it does not contain any harmful content, such as malicious scripts. When certain characters appear at specific locations within HTML markup, they...

A combination of clicks and key presses can lead to cross site scripting or code execution – Opera Security Advisories

When a user double clicks on a page, they may expect the two clicks to target the same object. If a page uses the first click to open a pop-up window in a predictable location, the second click may focus parts of the new window, such as its address field. If the page can then convince the user to...

History.state can leak the state data from cross domain pages – Opera Security Advisories

When a site uses history.pushState and history.replaceState to add or replace history entries, it can also provide optional data, which may typically be used to restore the given state when the user navigates through their browser history. When pages with cross-domain frames use this functionalit...

Web page dialogs can be used to to display the wrong address in the address field – Opera Security Advisories

The address field should always show the correct address for the page that is loaded. If a page can cause Opera to display certain dialogs relating to a target site, the dialog may in some cases cause Opera to display the target site’s address instead of the correct address. This can allow an...

Small windows can be used to trick users into executing downloads – Opera Security Advisories

When the download dialog is displayed, it should always be visible to the user, to ensure that the user realizes it is there. If the dialog is displayed in a small enough window, the user may not realize it is being displayed, and if the right keyboard sequence is carefully followed, they can end...

Frameset issue allows execution of arbitrary code – Opera Security Advisories

Framesets allow web pages to hold other pages inside them. Certain frameset constructs are not handled correctly when the page is unloaded, causing a memory corruption. To inject code, additional techniques will have to be employed...

Cross-domain checks may be bypassed, allowing limited data theft using CSS – Opera Security Advisories

Cross-domain checks may be bypassed, allowing limited data theft using CSS – Opera Security Advisories OPCOM Team | October 6, 2010 Severity Moderate Description CSS can be loaded cross-domain. In some cases, files that do not contain CSS may be partially interpreted as CSS. It is possible to mak...

Heap buffer overflow in HTML5 canvas can be used to execute arbitrary code – Opera Security Advisories

Heap buffer overflow in HTML5 canvas can be used to execute arbitrary code – Opera Security Advisories OPCOM Team | August 12, 2010 Severity High Description Performing some painting operations on a canvas while certain transformations are being applied in Opera may result in heap buffer overflow...

Certain characters may be used for domain name spoofing – Opera Security Advisories

Certain characters may be used for domain name spoofing – Opera Security Advisories OPCOM Team | June 29, 2010 Severity Moderately severe Description Opera uses several approaches to prevent spoofing of internationalized domain names IDN with characters that look similar to each other. With...

HTTP Content-Length header can be used to execute arbitrary code – Opera Security Advisories

HTTP Content-Length header can be used to execute arbitrary code – Opera Security Advisories OPCOM Team | March 17, 2010 Affected versions This vulnerability affects Opera for Microsoft Windows. Severity Highly Severe Description Large values in the HTTP Content-Length header can cause Opera to...

Sites using revoked intermediate certificates might be shown as secure – Opera Security Advisories

Sites using revoked intermediate certificates might be shown as secure – Opera Security Advisories OPCOM Team | August 29, 2009 Summary Opera does not check the revocation status for intermediate certificates not served by the server. If the intermediate is revoked, this might not impact the...

Newsfeed prompt can cause Opera to execute arbitrary code – Opera Security Advisories

Newsfeed prompt can cause Opera to execute arbitrary code – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Highly Severe Problem Description When Opera encounters a newsfeed source on a Web page, it prompts to add the source as a newsfeed. A script can manipulate the feed sourc...

Opera security upgrade for Linux, Solaris and FreeBSD – Opera Security Advisories

Opera security upgrade for Linux, Solaris and FreeBSD – Opera Security Advisories OPCOM Team | December 16, 2008 Summary Opera 9.20 has a highly recommended security upgrade for users of the Adobe Flash Player on Linux, Solaris and FreeBSD Severity Highly critical Problem description A security...

Feed links can link to local files

As a security precaution, Opera does not allow Web pages to link to files on the user's local disk. However, a flaw exists that allows Web pages to link to feed source files on the user's computer. Suitable detection of JavaScript events and appropriate manipulation can unreliably allow a script ...

History Search can be used to execute arbitrary code – Opera Security Advisories

History Search can be used to execute arbitrary code – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Extremely Severe Problem Description When certain parameters are passed to Opera’s History Search, they can cause content not to be correctly sanitized. This can allow scripts ...

Java applets can be used to read sensitive information – Opera Security Advisories

Java applets can be used to read sensitive information – Opera Security Advisories OPCOM Team | December 16, 2008 Severity: Highly Severe Problem Description Once a Java applet has been cached, if a page can predict the cache path for that applet, it can load the applet from the cache, causing it...

Registering Opera as a protocol handler can allow it to be used to execute arbitrary code – Opera Security Advisories

Registering Opera as a protocol handler can allow it to be used to execute arbitrary code – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Extremely Severe Problem Description When an application attempts to access a URL that uses a protocol that it does not understand, it may...

canvas functions can reveal data from random places in memory – Opera Security Advisories

canvas functions can reveal data from random places in memory – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Moderately severe Problem description There is a flaw in the way that certain canvas functions are handled, that can cause the canvas to be painted with very small...

Malformed JPEG headers can be used to execute arbitrary code – Opera Security Advisories

Malformed JPEG headers can be used to execute arbitrary code – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Extremely Severe Problem Description A specially crafted JPEG header can cause Opera to crash, allowing execution of arbitrary code. Opera’s Response Opera Software has...

Representation of DOM attribute values could allow cross-site scripting – Opera Security Advisories

Representation of DOM attribute values could allow cross-site scripting – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Moderately Severe Problem Description When XML is imported into a document, its attribute values are not correctly presented to the DOM. This can allow their...

Built-in XSLT templates can allow cross-site scripting – Opera Security Advisories

Built-in XSLT templates can allow cross-site scripting – Opera Security Advisories OPCOM Team | December 15, 2008 Severity Highly Severe Problem Description Built-in XSLT templates incorrectly handle escaped content and can cause it to be treated as markup. If a site accepts content from untruste...

Images can be read cross-domain with canvas

HTML CANVAS elements can use images as patterns, and that image data is made available to scripts. When the images are retrieved from other Web sites, the image data should no longer be available to scripts. A flaw exists in the way that Opera checks for the source of these images. Suitable...

Opera security upgrade for Mac OS X – Opera Security Advisories

Opera security upgrade for Mac OS X – Opera Security Advisories OPCOM Team | October 18, 2007 Opera security upgrade for Mac OS X. Severity: Highly Severe Affected Versions Mac OS X system with the Opera Web browser and the Adobe Flash Player 9.0.47.0 and earlier installed. Problem Description...

Very large link addresses can cause Opera to crash – Opera Security Advisories

Very large link addresses can cause Opera to crash – Opera Security Advisories OPCOM Team | October 17, 2006 Summary: Very large link addresses can cause Opera to crash. Severity: Moderate Problem description An extremely long link address can cause Opera to crash.A specially crafted long link...

The link tooltip and the statusbar can be misleading – Opera Security Advisories

The link tooltip and the statusbar can be misleading – Opera Security Advisories OPCOM Team | February 17, 2006 Summary Opera’s status bar shows the “title” attribute of a form inputimage, not the form’s “action” URL. This may mislead the user. Severity: Very low Problem description It is possibl...

A very long title in a web page can cause a crash on startup – Opera Security Advisories

A very long title in a web page can cause a crash on startup – Opera Security Advisories OPCOM Team | December 12, 2005 Summary A web page with an extremely long attribute can causeOpera to crash when certain conditions are met. It affectsWindows users with Input Method Editor IME installed...

Opera may execute command line embedded in URLs – Opera Security Advisories

Opera may execute command line embedded in URLs – Opera Security Advisories OPCOM Team | November 23, 2005 Summary Opera will execute command lines embedded in the URL when anotherprogram uses Opera to open a link. This affects UNIX versions ofOpera Linux/FreeBSD/Solaris. Severity: High Problem...

Data Privacy Day: Inside the role of Data Protection Officer at Opera

Privacy Data Privacy Day: Inside the role of Data Protection Officer at Opera Share January 28th, 2026 Privacy matters all year round. But every January, Data Privacy Day is a great opportunity to learn more about data privacy and protection, and to highlight their importance for everyone in the...

GameMaker security update: Patch now to prevent DoS attacks

Security GameMaker security update: Patch now to prevent DoS attacks Share October 30th, 2025 Today we’re looking at a vulnerability discovered in GameMaker, the game development tool that streamlines and simplifies game dev for all users, regardless of skill level. The vulnerability in question...

Update your browser: Security fix for Chrome zero-day CVE-2025-6554

News, Security Update your browser: Security fix for Chrome zero-day CVE-2025-6554 Share July 3rd, 2025 Hi everyone! The latest patches to the Opera, Opera GX, Opera Air, and Opera for Android address several recent vulnerabilities, including a zero-day exploit CVE-2025-6554. We recommend updatin...

VPNs explained: How a VPN helps keep your online life private

Privacy, Security VPNs explained: How a VPN helps keep your online life private Share July 1st, 2025 Today, we spend more than half our lives online. So it’s only natural that we worry a lot more about online safety and privacy. VPNs are just one of the tools many internet users already rely on t...

Update your browser: Security fixes for latest Chrome zero-day

News, Security Update your browser: Security fixes for latest Chrome zero-day Share June 5th, 2025 Hi everyone! The latest patches to the Opera, Opera GX, Opera Air, and Opera for Android address several recent vulnerabilities, including a zero-day exploit CVE-2025-5419. We recommend updating you...

Safe Browsing now on Opera for Android

Security Safe Browsing now on Opera for Android Share November 11th, 2022 Hi Android users! We’re happy to share that Opera for Android 72 now features Safe Browsing to keep you even safer when browsing or shopping online on your Android device. Safe Browsing protects your online experience by...

Opera Privacy Statement Update 2022

Privacy Opera Privacy Statement Update 2022 Share August 29th, 2022 Opera, a browser company based out of Oslo, Norway, cares deeply about user security and data protection. With that in mind, we actively work on improving our internal practices and communications with you, our users. We are maki...

Bug Bounty Adventures: A NodeBB 0-day

Research Bug Bounty Adventures: A NodeBB 0-day Share March 25th, 2022 Opera maintains both apublic bug bounty program, and a private program, where security researchers can submit security issues they have found in Opera’s products for cash rewards. We like to highlight some of the issues that ha...

$8,000 Bug Bounty Highlight: XSS to RCE in the Opera Browser

Research $8,000 Bug Bounty Highlight: XSS to RCE in the Opera Browser Share September 24th, 2021 Continuing from hisprevious post, Bug Bounty Hunter Renwa writes about the second vulnerability he submitted to Opera’s Private Bug Bounty Programme: a Remote Code Execution in Opera’s My Flow Feature...

Can a browser extension be cursed?

Privacy Can a browser extension be cursed? Share December 4th, 2020 Mallory tries to create a browser extension that will let him spy on Alice. TL;DR: skip to the conclusions to see what Alice learned. The Privacy Problem Mallory was quite tired of his failed attempts to melt Alice’s heart. She...

Opera Receives DevSecOps All-Star Award at SnykCon 2020

News Opera Receives DevSecOps All-Star Award at SnykCon 2020 Share October 28th, 2020 AtSnykCon 2020, Opera received the DevSecOps All-Star Award for leveraging Snyk to bring a complete and fully automated DevSecOps process into a secure software development lifecycle. Opera was represented by...

Flow is seamless and secure – security features explained

Security Flow is seamless and secure – security features explained Share August 28th, 2018 Some of you may already be familiar with Flow, the new feature that allows you to quickly and seamlessly share images, links and videos between your Opera browser for computers and your Opera Touch mobile...

Developer 32: Protecting against yourself

Security Developer 32: Protecting against yourself Share June 18th, 2015 Remember the SuperFish scandal? A third party application installed a Certificate Authority on PCs, and then hijacked all secure connections by serving browsers certificates from this local certificate authority. The SuperFi...

Cookies can be set for a top-level domain – Opera Security Advisories

Browsers should only allow cookies to be set for the website that created them. In some specific cases, Opera does not apply this restriction correctly, and allows a website to set a cookie for its entire top-level domain such as .com or .co.uk. A malicious site could then redirect the user to...

RC4 encryption protocol is vulnerable to certain brute force attacks – Opera Security Advisories

Weaknesses in the RC4 encryption protocol have been found, allowing an attacker to deduce the plaintext. If the same message is encrypted many millions of times, statistical methods can be used to extract valuable information, such as cookies. Due to the time this amount of requests takes, this i...

TLS response timings can indicate network contents – Opera Security Advisories

When Opera receives incorrectly encrypted network data, Opera will detect this, and let the sender know that the data was not understood. Such encrypted error responses are marginally faster than regular responses. An attacker with access to the network, can by replacing network data measure...

DOM events manipulation might be used to execute arbitrary code – Opera Security Advisories

DOM events manipulation might be used to execute arbitrary code – Opera Security Advisories OPCOM Team | January 29, 2013 Severity: High Description: Particular DOM event manipulations can cause Opera to crash. In some cases, this crash might occur in a way that allows execution of arbitrary code...

Use of SVG clipPaths can allow execution of arbitrary code – Opera Security Advisories

When SVG documents with specifically prepared clipPaths are used in Opera, Opera may allow other content to overwrite the memory, before referencing the memory, which will lead to a crash. If an attacker can control the contents being written into memory, execution of arbitrary code may occur...

Plug-in content may monitor keystrokes on unrelated pages – Opera Security Advisories

Plug-ins may use operating system features to detect key presses when the plug-in is focused. If the plug-in does not detect its own focused state correctly, it can detect key presses when other pages are focused, allowing the plug-in content to detect key presses intended for pages from other...

Carefully timed reloads, redirects, and navigation can spoof the address field – Opera Security Advisories

The address field should always show the address of the page that is being displayed. Certain types of navigation, combined with reloads and redirects to a slowly-responding target site can cause the address field to show the target site’s address, while the attacking site is still being displaye...