Memory corruption during text run construction (Windows) — Mozilla

Alex Miller reported that when very long strings were constructed and inserted into an HTML document, the browser would incorrectly construct the layout objects used to display the text. Under such conditions an incorrect length would be calculated for a text run resulting in too small of a memor...

Buffer overflow in JavaScript upvarMap — Mozilla

Security researcher Christian Holler reported that the JavaScript engine's internal memory mapping of non-local JS variables contained a buffer overflow which could potentially be used by an attacker to run arbitrary code on a victim's computer...

Chrome privilege escalation due to incorrectly cached wrapper — Mozilla

Mozilla add-on developer and community member Wladimir Palant reported broken functionality on pages that had a Link: HTTP header when an add-on was installed which implemented a Content Policy in JavaScript, such as AdBlock Plus or NoScript. Mozilla security researcher mozbugra4 demonstrated tha...

Heap overflow in certificate regexp parsing — Mozilla

Moxie Marlinspike reported a heap overflow vulnerability in the code that handles regular expressions in certificate names. This vulnerability could be used to compromise the browser and run arbitrary code by presenting a specially crafted certificate to the client. This code provided compatibili...

Mozilla Firefox XUL Linked Clones Double Free Vulnerability — Mozilla

An anonymous researcher, via TippingPoint's Zero Day Initiative program, reported a vulnerability in Mozilla's garbage collection process. The vulnerability was caused by improper memory management of a set of cloned XUL DOM elements which were linked as a parent and child. After reloading the...

Additional XSS attack vectors in feed preview — Mozilla

Mozilla security researcher mozbugra4 reported an additional variation on the feed preview vulnerabilities fixed in Firefox 2.0.0.17. mozbugra4 demonstrated that it was still possible to use the feed preview as a vector for JavaScript privilege escalation. An attacker could use this issue to run...

Privilege escalation using feed preview page and XSS flaw — Mozilla

Mozilla security researcher mozbugra4 reported a series of vulnerabilities in feedWriter which allow scripts from page content to run with chrome privileges...

XSS through JavaScript same-origin violation — Mozilla

Mozilla contributor mozbugra4 submitted a set of vulnerabilities which allow scripts from one document to be executed in the context of a different document. These vulnerabilities could be used by an attacker to violate the same-origin policy and perform an XSS attack against arbitrary sites,...

XUL popup spoofing variant (cross-tab popups) — Mozilla

Mozilla contributor Chris Thomas demonstrated that it was possible to have a background tab create a borderless XUL pop-up in front of the active tab in the user's browser. This technique could be used by an attacker to spoof form elements such as a login prompt for a site opened in a different t...

XUL pages can hide the window titlebar — Mozilla

Mozilla developer Eli Friedman discovered that web pages written in the XUL markup language rather than the usual HTML can hide their window's titlebar. It may have been possible to abuse this ability to create more convincing spoof and phishing pages...

Path Abuse in Cookies — Mozilla

Nicolas Derouet reported two problems with cookie handling in Mozilla clients. The first was that the cookie path parameter was not subject to any length checks, and this could be abused to cause the victim's browser to use excessive amounts of memory while it was running as well as waste the dis...

Crashes with evidence of memory corruption (rv:1.8.0.12/1.8.1.4) — Mozilla

As part of the Firefox 2.0.0.4 and 1.5.0.12 update releases Mozilla developers fixed many bugs to improve the stability of the product. Some of these crashes that showed evidence of memory corruption under certain circumstances and we presume that with enough effort at least some of these could b...

RSA Signature Forgery — Mozilla

Philip Mackenzie and Marius Schilder of Google informed us of Daniel Bleichenbacher's recent presentation of a common implementation error in RSA signature verification, a failure to account for extra data in the signature. For signatures with a small exponent such as 3 it is possible for an...

Double-free on malformed VCard — Mozilla

Masatoshi Kimura reported a hang caused by a double-free in Thunderbird when processing a large VCard with invalid base64 characters in it. Since an attacker can supply an arbitrary amount of well-formed VCard data before introducing the error we presume this could be exploited to run code of the...

cross-site scripting through window.controllers — Mozilla

shutdown demonstrated how to use the window.controllers array to bypass same-origin protections, allowing a malicious site to inject script into content from another site. This could allow the malicious page to steal information such as cookies or passwords from the other site, or perform...

Privilege escalation using a JavaScript function's cloned parent — Mozilla

shutdown discovered it was possible to use the Object.watch method to access an internal function object the "clone parent" which could then be used to run arbitrary JavaScript code with full permission. This could be used to install malware such as password sniffers or viruses...

Spoofing download and security dialogs with overlapping windows — Mozilla

Michael Krax demonstrates that the download dialog and security dialogs can be spoofed by partially covering them with an overlapping window. Some users may not notice the OS window border and browser statusbar bisecting what appears to be a single dialog, and be convinced by the spoofing text of...

Security Vulnerabilities fixed in Firefox ESR 140.17 — Mozilla

Note : We have changed how we publish advisories. We no longer roll all internally identified memory safety vulnerabilities into a single CVE and are now issuing an advisory for every individual bug. CVE-2026-100756: Incorrect boundary conditions in the Audio/Video: Playback component Reporter...

Security Vulnerabilities fixed in Firefox ESR 115.30 — Mozilla

CVE-2025-13012: Race condition in the Graphics component Reporter Irvan Kurniawan Impact high References Bug 1991458 CVE-2025-13013: Mitigation bypass in the DOM: Core & HTML component Reporter Masato Kinugawa Impact moderate References Bug 1991945 CVE-2025-13014: Use-after-free in the Audio/Vide...

Security Vulnerabilities fixed in Thunderbird 128.10 — Mozilla

Thunderbird's update mechanism allowed a medium-integrity user process to interfere with the SYSTEM-level updater by manipulating the file-locking behavior. By injecting code into the user-privileged process, an attacker could bypass intended access controls, allowing SYSTEM-level file operations...

Security Vulnerabilities fixed in Thunderbird 128.5 — Mozilla

Certain WebGL operations on Apple silicon M series devices could have lead to an out-of-bounds write and memory corruption due to a flaw in Apple's GPU driver. This bug only affected the application on Apple M series hardware. Other platforms were unaffected. An attacker could cause a select...

Security Vulnerabilities fixed in Focus for iOS 130 — Mozilla

Websites could utilize Javascript links to spoof URL addresses in the Focus navigation bar...

Security Vulnerabilities fixed in Firefox ESR 115.4 — Mozilla

It was possible for certain browser prompts and dialogs to be activated or dismissed unintentionally by the user due to an insufficient activation-delay. An attacker could have created a malicious link using bidirectional characters to spoof the location in the address bar when visited. Drivers a...

Information stealing via form history — Mozilla

Security researcher Paul Stone reported that a Java applet could be used to mimic interaction with form autocomplete controls and steal entries from the form history...

ParanoidFragmentSink allows javascript: URLs in chrome documents — Mozilla

Security researcher Roberto Suggi Liverani reported that ParanoidFragmentSink, a class used to sanitize potentially unsafe HTML for display, allows javascript: URLs and other inline JavaScript when the embedding document is a chrome document. While there are no unsafe uses of this class in any...

Browser chrome defacement via cached XUL stylesheets — Mozilla

Mozilla developer Wladimir Palant reported that stylesheets used in remote XUL documents can wind up in the XUL cache where it can later be accessed by browser chrome for use in styling the user interface. A malicious website could use this issue to pollute a user's XUL cache and change style...

Chrome privilege escalation with FeedWriter — Mozilla

Mozilla security researcher mozbugra4 reported that the BrowserFeedWriter could be leveraged to run JavaScript code from web content with elevated privileges. Using this vulnerability, an attacker could construct an object containing malicious JavaScript and cause the FeedWriter to process the...

Malicious search plugins can inject code into arbitrary sites — Mozilla

Security researcher Prateek Saxena reported that a malicious MozSearch plugin could be created using a javascript: URI in the SearchForm value. This URI is used as the default landing page when an empty search is performed. If an attacker could get a user to install the malicious plugin and perfo...

XSL Transformation vulnerability — Mozilla

Security researcher Guido Landi discovered that a XSL stylesheet could be used to crash the browser during a XSL transformation. An attacker could potentially use this crash to run arbitrary code on a victim's computer...

nsXMLHttpRequest::NotifyEventListeners() same-origin violation — Mozilla

Mozilla security researcher mozbugra4 reported that the same-origin check in nsXMLHttpRequest::NotifyEventListeners could be bypassed. This vulnerability could be used to execute JavaScript in the context of a different website...

Crashes with evidence of memory corruption (rv:1.8.1.8) — Mozilla

As part of the Firefox 2.0.0.8 update releases Mozilla developers fixed many bugs to improve the stability of the product. Some of these crashes showed evidence of memory corruption under certain circumstances and we presume that with enough effort at least some of these could be exploited to run...

Code execution via QuickTime Media-link files — Mozilla

On his blog Petko D. Petkov reported that QuickTime Media-Link files contain a qtnext attribute that could be used on Windows systems to launch the default browser with arbitrary command-line options. When the default browser is Firefox 2.0.0.6 or earlier use of the -chrome option allowed a remot...

Mail header processing heap overflows — Mozilla

Georgi Guninski reported that long Content-Type headers in external message bodies could cause a heap buffer overflow when processing mail headers. While working on that code David Bienvenu discovered a similar overflow could occur when processing long rfc2047-encoded headers...

Deleted object reference when designMode="on" — Mozilla

Martijn Wargers and Nick Mott each described crashes that were discovered to ultimately stem from the same root cause: attempting to use a deleted controller context when designMode was turned on. This generally results in crashing the browser, but in theory references to deleted objects can be...

Integer overflows in E4X, SVG, and Canvas — Mozilla

Georgi Guninski reports integer overflows in the new E4X, SVG, and Canvas features. These lead to memory corruption that is potentially exploitable to run arbitrary code...

Security Vulnerabilities fixed in Thunderbird 148 — Mozilla

Memory safety bugs present in Firefox 147 and Thunderbird 147. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. Memory safety bugs present in Firefox ESR 140.7, Thunderbird ESR 140.7,...

Security Vulnerabilities fixed in Firefox ESR 128.13 — Mozilla

On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. On arm64, a WASM brtable instruction with a lot of entries could lead to the label being too far from the instruction causing truncation and incorrec...

Security Vulnerabilities fixed in Firefox ESR 115.23.1 — Mozilla

An attacker was able to perform an out-of-bounds read or write on a JavaScript Promise object. An attacker was able to perform an out-of-bounds read or write on a JavaScript object by confusing array index sizes...

Security Vulnerabilities fixed in Thunderbird 134 — Mozilla

The Matrix specification demands homeservers to perform validation of the server-name and media-id components of MXC URIs with the intent to prevent path traversal. However, it is not mentioned that a similar check must also be performed on the client to prevent client-side path traversal...

Security Vulnerabilities fixed in Firefox ESR 128.4 — Mozilla

A permission leak could have occurred from a trusted site to an untrusted site via embed or object elements. An attacker could have caused a use-after-free when accessibility was enabled, leading to a potentially exploitable crash. The origin of an external protocol handler prompt could have been...

Security Vulnerabilities fixed in Thunderbird 128.2 — Mozilla

When aborting the verification of an OTR chat session, an attacker could have caused a use-after-free bug leading to a potentially exploitable crash. A difference in the handling of StructFields and ArrayTypes in WASM could be used to trigger an exploitable type confusion vulnerability. A...

Buffer overflow in JavaScript atom map — Mozilla

Security researcher Christian Holler reported that the JavaScript engine's internal mapping of string values contained an error in cases where the number of values being stored was above 64K. In such cases an offset pointer was manually moved forwards and backwards to access the larger address...

Use-after-free error with nsDOMAttribute MutationObserver — Mozilla

Security researcher regenrecht reported via TippingPoint's Zero Day Initiative that a nsDOMAttribute node can be modified without informing the iterator object responsible for various DOM traversals. This flaw could lead to a inconsistent state where the iterator points to an object it believes i...

Buffer overflow while line breaking after document.write with long string — Mozilla

Dirk Heinrich reported that on Windows platforms when document.write was called with a very long string a buffer overflow was caused in line breaking routines attempting to process the string for display. Such cases triggered an invalid read past the end of an array causing a crash which an...

Arbitrary code execution via Flash Player dynamic module unloading — Mozilla

An anonymous security researcher reported via TippingPoint's Zero Day Initiative that insufficient checks were being performed to test whether the Flash module was properly dynamically unloaded. The researcher demonstrated that a SWF file which dynamically unloads itself from an outside JavaScrip...

Multiple XSS vulnerabilities from character encoding — Mozilla

WebKit developer Alexey Proskuryakov reported that the Mozilla HTML parser treated the backspace character as whitespace contrary to the HTML specification and different from other browsers. This difference might lead to Cross-site Scripting XSS risks on sites which filtered input in accordance...

XPCNativeWrapper pollution — Mozilla

Mozilla security researchers shutdown and mozbugra4 reported two separate ways to modify an XPCNativeWrapper such that subsequent access by the browser would result in executing user-supplied code...

Privilege escallation using an event handler attached to an element not in the document — Mozilla

An attacker can use an element outside of a document to call an event handler allowing content to run arbitrary code with chrome privileges...

JavaScript execution in mail via XBL — Mozilla

Georgi Guninski demonstrated that even with JavaScript disabled in mail the default an attacker can still execute JavaScript when a mail message is viewed, replied to, or forwarded by putting the script in a remote XBL file loaded by the message. The executed script could be used to alter or chan...

PLUGINSPAGE privileged JavaScript execution II — Mozilla

Paul Nickerson reports that the fix for MFSA 2005-34 can be bypassed using nested javascript: URLs, again allowing the attacker to execute privileged code. The attacker must first convince the user to first click on the missing-plugin icon in the page or the "Install Missing Plugins..." button in...