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...

External news readers and e-mail clients can be used to execute arbitrary code

If a user has configured Opera to use an external newsgroup client or e-mail application, specially crafted Web pages can cause Opera to run that application incorrectly. In some cases this can lead to execution of arbitrary code...

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...

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...

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...

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...

Replaced code signing certificate – Opera Security Advisories

Opera Software recently experienced an attack on the internal infrastructure. Following best practices, Opera Software is replacing signing certificates in Opera with newly issued certificates. Certificates in Opera include the code signing certificate for desktop binaries and the signing...

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...

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...

Opera may be used as a vector for a font issue in the underlying operating system – Opera Security Advisories

Opera may be used as a vector for a font issue in the underlying operating system – Opera Security Advisories OPCOM Team | June 19, 2010 Affected versions This vulnerability may be targeted through Opera for Windows. Severity Extremely Severe Description A flaw in the font handling on the Windows...

TLS certificates can be used to execute arbitrary code

When connecting to a TLS-protected website, Opera parses the X.509 certificate. If a site uses a specially crafted Subject Alternative Name in the certificate, it can cause Opera to crash. To inject code, additional means will have to be employed...

TLS certificates can be used to execute arbitrary code – Opera Security Advisories

TLS certificates can be used to execute arbitrary code – Opera Security Advisories OPCOM Team | February 13, 2009 Severity Highly Severe Problem Description When connecting to a TLS-protected website, Opera parses the X.509 certificate. If a site uses a specially crafted Subject Alternative Name ...

Simulated text inputs can trick users into uploading arbitrary files

When a user types into a file input, scripts can cause some of the keystrokes to be ignored. If the script can convince the user that they are typing into a normal text input, and not let them see that their keystrokes are being ignored, it can cause the input to point to known file paths on the...

History Search can reveal browsing history – Opera Security Advisories

History Search can reveal browsing history – Opera Security Advisories OPCOM Team | December 16, 2008 Severity Extremely Severe Platforms All desktop versions Problem Description Certain constructs are not escaped correctly by Opera’s History Search results. These can be used to inject scripts in...

Feed preview can reveal contents of unrelated news feeds

When Opera is previewing a news feed, some scripts are not correctly blocked. These scripts are able to subscribe the user to any feed URL that the attacker chooses, and can also view the contents of any feeds that the user is subscribed to. These may contain sensitive information...

Rich editing allows cross domain scripting

Rich editing using designMode allows page contents to be edited. Pages can use this ability to inject scripts into pages from other domains. This allows cross domain scripting...

Malicious torrent files can execute arbitrary code in Opera – Opera Security Advisories

Malicious torrent files can execute arbitrary code in Opera – Opera Security Advisories OPCOM Team | May 24, 2007 Summary A malicious torrent file can cause Opera to execute arbitrary code. Severity: Highly critical Problem description A specially crafted torrent file can cause a buffer overflow ...

Opera security advisory 2004-12-10 – Opera Security Advisories

Opera security advisory 2004-12-10 – Opera Security Advisories OPCOM Team | February 9, 2007 Opera security advisory Named frames or windows can be hi-jacked by malicious frames or windows. Periods in the file name and non-breaking spaces in the Content-Type header can make the save/open dialog...

Update your browser: Security fix for Chrome zero-day CVE-2025-13223

News, Security Update your browser: Security fix for Chrome zero-day CVE-2025-13223 Share November 20th, 2025 Hi everyone! The latest patches to Opera, Opera GX, Opera Air, and Opera for Android address several recent vulnerabilities, including a zero-day exploit CVE-2025-13223. We recommend...

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-2025-6558

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...

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 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...

New Opera 93 Stable update includes fix for latest Chromium zero-day

Security New Opera 93 Stable update includes fix for latest Chromium zero-day Share December 2nd, 2022 Hi everyone! Opera for Windows and Mac have received Stable updates 93.0.4585.37 and 93.0.4585.39 respectively. Among other things, these updates include Chromium update 107.0.5304.122, which...

Address bar spoofing in Opera Mini for Android – Opera Security Advisories

Opera Mini for Android before version 52.2 is vulnerable to an address bar spoofing attack. The vulnerability allows a malicious page to trick the browser into showing an address of a different page. This may allow the malicious page to impersonate another page and trick a user into providing...

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...

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...

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...

HTTP response heap buffer overflow can allow execution of arbitrary code – Opera Security Advisories

When requesting pages using HTTP, Opera temporarily stores the response in a buffer. In some cases, Opera may incorrectly allocate too little space for a buffer, and may then store too much of the response in that buffer. This causes a buffer overflow, which in turn can lead to a memory corruptio...

The wrong executable may be used to display a downloaded file in its folder – Opera Security Advisories

The wrong executable may be used to display a downloaded file in its folder – Opera Security Advisories OPCOM Team | January 28, 2011 Severity Low Affected versions This issue affects Opera for Microsoft Windows. Description Opera’s downloads manager allows users to select a file, and open the...

Reloads and redirects can allow spoofing and cross site scripting – Opera Security Advisories

Reloads and redirects can allow spoofing and cross site scripting – Opera Security Advisories OPCOM Team | October 6, 2010 Severity Critical Description Scripts on a page are supposed to be restricted so that they can only interact with other pages from the same domain and security context...

Opera may be used as a vector for a font issue in the underlying operating system

A flaw in the font handling on the Windows operating system has been fixed by Microsoft. On unpatched systems, Web fonts may be used to exploit this issue through Opera...

Heap buffer overflow in string to number conversion – Opera Security Advisories

Passing very long strings through the string to number conversion using JavaScript in Opera may result in heap buffer overflows. This also affects the dtoa routine, and was reported in CVE-2009-0689. In most cases Opera will just freeze or terminate, but in some cases this could lead to a crash...

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...

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...

Newsfeed prompt can cause Opera to execute arbitrary code

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 source in a way that can cause Opera to crash. The crash is caused by an erroneous memory access. To inject code, additional techniques will have to be employed...

Long hostnames in file: URLs can cause execution of arbitrary code – Opera Security Advisories

Long hostnames in file: URLs can cause execution of arbitrary code – Opera Security Advisories OPCOM Team | December 15, 2008 Severity Highly Severe Problem Description Exceptionally long host names in file: URLs can cause a buffer overflow, which may be exploited to execute arbitrary code. Remot...

HTML parsing flaw can cause Opera to execute arbitrary code – Opera Security Advisories

HTML parsing flaw can cause Opera to execute arbitrary code – Opera Security Advisories OPCOM Team | December 15, 2008 Severity Extremely Severe Problem Description Certain HTML constructs can cause the resulting DOM to change unexpectedly, which triggers a crash. To inject code, additional...

Images can be read cross-domain with canvas – Opera Security Advisories

Images can be read cross-domain with canvas – Opera Security Advisories OPCOM Team | June 9, 2008 Severity: Less Severe Problem Description 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...

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...

Information displayed in the security field should be approached with caution. – Opera Security Advisories

Information displayed in the security field should be approached with caution. – Opera Security Advisories OPCOM Team | February 9, 2007 Summary Even though a Certificate Authority has verified and signed it, a usershould not trust the Organization name without checking the domain name.A fraudule...

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...

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...

Update your browser: Security fix for Chrome zero-day CVE‑2026‑85046

News, Security Update your browser: Security fix for Chrome zero-day CVE‑2026‑85046 Share September 8th, 2026 Hi everyone! The latest patches to Opera’s browsers address several recent vulnerabilities, including a zero-day exploit CVE‑2026‑85046. We recommend updating your browsers to the latest...

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...

Update your browser: Security fix for Chrome zero-day CVE-2025-14174

News, Security Update your browser: Security fix for Chrome zero-day CVE-2025-14174 Share December 18th, 2025 Hi everyone! The latest patches to Opera, Opera GX, Opera Air, and Opera for Android address several recent vulnerabilities, including a zero-day exploit CVE-2025-14174. We recommend...

Addressing the “CrossBarking” vulnerability discovered in collaboration with Guardio

News, Security Addressing the “CrossBarking” vulnerability discovered in collaboration with Guardio Share October 30th, 2024 Hi Opera users! Over time, we have shared details about how we approach security vulnerabilities, and especially how we work with external security researchers to identify...

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 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,...

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...