data: URLs can spoof trusted trusted sites

data: URLs embed data inside them, instead of linking to an externalresource. Opera can mistakenly display the end of a data URL insteadof the beginning. This allows an attacker to spoof the URL of atrusted site...

The createPattern function can reveal old data from random places in memory – Opera Security Advisories

The createPattern function can reveal old data from random places in memory – Opera Security Advisories OPCOM Team | July 19, 2007 Summary The createPattern function can reveal old data from random places in memory Severity: moderately severe Problem description Opera for Linux, FreeBSD, and...

A forged SSL server certificate can be accepted by Opera as a valid certificate

A specially crafted digital certificate can bypass Opera'scertificate signature verification. Forged certificatescan contain any false information the forger chooses, andOpera will still present it as valid. Opera will not presentany warning dialogs in this case, and the security statuswill be th...

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...

Specially crafted Java applets can crash Opera – Opera Security Advisories

Specially crafted Java applets can crash Opera – Opera Security Advisories OPCOM Team | November 23, 2005 Summary A specially crafted Java applet can cause Opera to crash. Severity: Not exploitable Problem description Java code using LiveConnect methods to remove a property of aJavaScript object...

Malicious setRequestHeader cross-site vulnerability

A malicious setRequestHeader can be used to stealuser credentials and inject cross-site JavaScript...

Update your browser: Security fix for Chrome zero-day CVE-2026-5281

News, Security Update your browser: Security fix for Chrome zero-day CVE-2026-5281 Share April 4th, 2026 Hi everyone! The latest patches to Opera’s browsers address several recent vulnerabilities, including a zero-day exploit CVE-2026-5281. We recommend updating your browsers to the latest versio...

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...

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...

Heartbleed and other heartaches

Security Heartbleed and other heartaches Share April 11th, 2014 As has been reported extensively already, OpenSSL just fixed a serious vulnerability, dubbed Heartbleed. OpenSSL is used in a variety of products used on the internet, including Opera products and servers. We want to share with you h...

CORS requests can omit the preflight request – Opera Security Advisories

Cross-Origin Resource Sharing CORS requests are required to send a preflight request if custom headers are included, to check that the host wishes to allow the full request to be made. An example of where this may be needed is for sites that use a custom header with a static value as part of thei...

Heap buffer overflow in HTML5 canvas can be used to execute arbitrary code

Performing some painting operations on a canvas while certain transformations are being applied in Opera may result in heap buffer overflows. In most cases Opera will just freeze or terminate, but in some cases this could lead to a crash which could be used to execute code. To inject code,...

History Search can reveal browsing history

Certain constructs are not escaped correctly by Opera's History Search results. These can be used to inject scripts into the page, which can then be used to look through the user's browsing history, including the contents of the pages they have visited. These may contain sensitive information...

Feed subscription can cause the wrong page address to be displayed – Opera Security Advisories

Feed subscription can cause the wrong page address to be displayed – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Not Severe Problem Description It has been reported that when a user subscribes to a news feed using the feed subscription button, the page address can be changed...

Image properties can be used to execute scripts – Opera Security Advisories

Image properties can be used to execute scripts – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Highly Severe Problem Description Image properties can contain custom comments. When displaying the image properties, Opera can be tricked into treating the comments as script. This...

Resized canvas patterns can cause Opera to execute arbitrary code

HTML CANVAS elements can use scaled images as patterns. With suitable scaling manipulation of the image, a script can cause Opera to crash. This crash can sometimes cause memory corruption. To inject code, additional techniques will have to be employed...

Startup crash can allow execution of arbitrary code

When Opera is registered as a handler for a given protocol, it can be started by external applications. In some cases, being started in this way can cause Opera to crash. To inject code, additional techniques will have to be employed...

Character Encoding Inheritance in iframes Can Enable Cross-Site Scripting

Pages displayed inside an iframe will inherit the character encodingof the parent page, unless they specify their own character encoding.A malicious page that uses the UTF-7 character encoding can includeother sites, for example inside iframes. This can be exploited toperform cross-site scripting...

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...

Opera's HTTP authentication cuts off long server names at the end

Opera's HTTP authentication dialog is displayed when the user enters a Web pagethat requires a login name and a password. To inform the user which server itwas that asked for login credentials, the dialog displays the server name.The user has to see the entire server name. A truncated name can be...

Malicious WMF files stored in Opera’s cache can infect Windows – Opera Security Advisories

Malicious WMF files stored in Opera’s cache can infect Windows – Opera Security Advisories OPCOM Team | January 13, 2006 Summary Windows Meta Files .wmf can contain executable code. A specially craftedWMF file can infect Microsoft Windows with malicious software when it is openedwith Windows’ own...

Combinations of right-to-left text and negative margins can crash Opera – Opera Security Advisories

Combinations of right-to-left text and negative margins can crash Opera – Opera Security Advisories OPCOM Team | November 23, 2005 Summary Combinations of right-to-left text and negative marginsin HTML code can crash Opera. Severity: Not a security issue. Problem description Right-to-left scripts...

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...

Prompt injection in Opera Neon: Rapid response through responsible disclosure

Security Prompt injection in Opera Neon: Rapid response through responsible disclosure Share October 23rd, 2025 Hi Opera users, This week, we were able to address a real-world security scenario on Opera Neon thanks to the work of a security researcher team. The researchers reached out to us throu...

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...

Does the TunnelVision vulnerability affect Opera’s free VPN?

Privacy Does the TunnelVision vulnerability affect Opera’s free VPN? Share June 12th, 2024 Hello! You may have heard recently about a new type of vulnerability called TunnelVision that makes it possible for a malicious actor to bypass VPN protection. So you will be happy to know that Opera’s free...

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

News, Security Update your browser: Security fixes for latest Chrome zero-day Share December 22nd, 2023 Hi everyone! The latest patches to the Opera, Opera GX, Opera Crypto, and Opera for Android browsers address several recent vulnerabilities, including a zero-day exploit CVE-2023-7024. We...

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

News, Security Update your browser: Security fix for latest Chrome zero-day Share September 29th, 2023 Hi everyone! Opera browsers have received important updates addressing a number of vulnerabilities and bugs. Among those is the following zero-day vulnerability detected by security researchers,...

Opera’s Security team at Barcelona Cybersecurity Congress 2023

Security Opera’s Security team at Barcelona Cybersecurity Congress 2023 Share February 9th, 2023 Hello readers! If you follow our Security team’s Twitter account it’s here, by the way!, you’ll have noticed we were busy last week meeting cybersecurity enthusiasts and professionals at this year’s...

Misissued certificates

Security Misissued certificates Share October 29th, 2015 Recently, Google found a google.com pre-certificate in a CT log, without having ordered one. This lead to a series of incidents, also involving Opera and its security team. The backstory Google promptly contacted Symantec who had issued the...

Dealing with FREAK and SuperFish

Security Dealing with FREAK and SuperFish Share March 10th, 2015 The FREAK TLS attack Following the trend of memorable names for TLS attacks, FREAK was recently announced. This exploits a bug in some TLS libraries, combined with the support of ancient weak ciphers, to enable a MitM to force...

Security changes and features of Opera 18

News Security changes and features of Opera 18 Share December 4th, 2013 Opera 18 is now out on the stable channel, so we wanted to take a moment to go through some of the new features from a security perspective. Media Access One of the new features is media access. That is; camera and microphone...

New home for the Security Group blog

News New home for the Security Group blog Share October 31st, 2013 Welcome to the new home of the Opera Security Group. We have changed our blogging platform. For more more information regarding the switch, please see this post. If you received this blog post in your feed reader, you do not need ...

Cross domain access to object constructors can be used to facilitate cross-site scripting – Opera Security Advisories

JavaScripts are able to redefine and override the methods of native objects. They may also do this with the native objects of any document that shares the same origin. By redefining the methods of another document through the constructor property of the document’s host objects, a malicious script...

Changing from a single-user to a multi-user installation on Windows (rev2) – Opera Security Advisories

Changing from a single-user to a multi-user installation on Windows rev2 – Opera Security Advisories OPCOM Team | January 5, 2012 If you received the error message “There was a problem initializing Opera Mail. Engine Init Failed”, it may mean that you have a stand-alone USB installation of Opera...

Opera may allow scripts to access feeds

Opera may allow scripts to run on the feed subscription page, thereby gaining access to the feeds object. This can be used for automatic subscription of feeds, or reading other feeds...

Opera security upgrade for Linux, Solaris and FreeBSD

A security issue in the Adobe Flash Player running in Opera on Linux, Solaris or FreeBSD has been found. Details about the vulnerability will be disclosed at a later date...

Vulnerability in createSVGTransformFromMatrix (JavaScript, SVG) – Opera Security Advisories

Vulnerability in createSVGTransformFromMatrix JavaScript, SVG – Opera Security Advisories OPCOM Team | December 16, 2008 Summary A vulnerability in createSVGTransformFromMatrix ObjectTypecasting can crash Opera. Severity Moderate Problem description Passing an incorrect object to...

Malformed bitmaps can reveal old data from random places in memory – Opera Security Advisories

Malformed bitmaps can reveal old data from random places in memory – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Moderately Severe Problem Description Specially malformed bitmap images can cause Opera to render the image using a palette made up from uninitialized memory. Usi...

Resized canvas patterns can cause Opera to execute arbitrary code – Opera Security Advisories

Resized canvas patterns can cause Opera to execute arbitrary code – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Moderately Severe Problem Description HTML CANVAS elements can use scaled images as patterns. With suitable scaling manipulation of the image, a script can cause...

Startup crash can allow execution of arbitrary code – Opera Security Advisories

Startup crash can allow execution of arbitrary code – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Extremely Severe Problem Description When Opera is registered as a handler for a given protocol, it can be started by external applications. In some cases, being started in this...

Sites can change framed content on other sites – Opera Security Advisories

Sites can change framed content on other sites – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Highly Severe Problem Description Scripts are able to change the addresses of framed pages that come from the same site. Due to a flaw in the way that Opera checks what frames can be...

A forged SSL server certificate can be accepted by Opera as a valid certificate – Opera Security Advisories

A forged SSL server certificate can be accepted by Opera as a valid certificate – Opera Security Advisories OPCOM Team | September 21, 2006 Summary: A forged SSL server certificate can be accepted by Opera as a valid certificate. Severity: Highly critical Vulnerable versions: Opera for desktop...

Internationalized domain names (IDN) can be used for spoofing. – Opera Security Advisories

Internationalized domain names IDN can be used for spoofing. – Opera Security Advisories OPCOM Team | February 25, 2005 Summary Opera supports internationalized domain names IDN, which allowsfor example Russian or Chinese domain names to be written in theirown native scripts. However, this also...

Protected with Opera Neon: Understanding agentic browser security

Security Protected with Opera Neon: Understanding agentic browser security Share October 21st, 2025 Hi Opera users, If you were hanging out around these parts in the past few weeks, you might have noticed that we launched Opera Neon – an AI agentic browser that can browse with you or for you, tak...

Update your browser: Security fix for Chrome zero-day CVE-2025-6558

News, Security Update your browser: Security fix for Chrome zero-day CVE-2025-6558 Share July 17th, 2025 Hi everyone! The latest patches to the Opera, Opera GX, and Opera Air address several recent vulnerabilities, including a zero-day exploit CVE-2025-6558. We recommend updating your browsers to...

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 January 18th, 2024 Hi everyone! The latest patches to the Opera, Opera GX, Opera Crypto, and Opera for Android browsers address several recent vulnerabilities, including a zero-day exploit CVE-2024-0519. We...

Update your browser: Security fixes for latest Chrome bugs

News, Security Update your browser: Security fixes for latest Chrome bugs Share December 1st, 2023 Hi everyone! The latest patches to the Opera, Opera GX, and Opera Crypto browsers address several recent vulnerabilities, including a zero-day exploit CVE-2023-6345. We recommend updating your...

Opera Privacy Statement Update 2019

Privacy Opera Privacy Statement Update 2019 Share February 7th, 2019 This is an outdated article. Please read Opera Privacy Statement Update 2022 instead. We have recently updated our end-user license agreements and our terms of service have been updated as well. We are also about to update our...