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Products by Mozilla Sorted by Most Security Vulnerabilities since 2018

Mozilla Firefox2150 vulnerabilities
Open source web browser

Mozilla Thunderbird1382 vulnerabilities
Email client

Mozilla FireFox Extended Support Release (ESR)1125 vulnerabilities

Mozilla SeaMonkey286 vulnerabilities
Browser, email and newsgroup client

Mozilla Thunderbird Esr217 vulnerabilities

Mozilla Network Security Services28 vulnerabilities

Mozilla Focus23 vulnerabilities

Mozilla Firefox Mobile21 vulnerabilities

Mozilla Firefox Focus17 vulnerabilities

Mozilla9 vulnerabilities

Mozilla Nss8 vulnerabilities

Mozilla Firefox Os5 vulnerabilities

Mozilla Vpn4 vulnerabilities

Mozilla Nunjucks1 vulnerability

Mozilla Zamboni1 vulnerability

Mozilla Netscape Portable Runtime1 vulnerability

Recent Mozilla Security Advisories

Advisory	Title	Published
mfsa2026-45	Security Vulnerabilities fixed in Firefox 150.0.3 mfsa2026-45	May 12, 2026
mfsa2026-44	Security Vulnerabilities fixed in Thunderbird 140.10.2 mfsa2026-44	May 8, 2026
mfsa2026-43	Security Vulnerabilities fixed in Thunderbird 150.0.2 mfsa2026-43	May 8, 2026
mfsa2026-40	Security Vulnerabilities fixed in Firefox 150.0.2 mfsa2026-40	May 7, 2026
mfsa2026-41	Security Vulnerabilities fixed in Firefox ESR 140.10.2 mfsa2026-41	May 7, 2026
mfsa2026-42	Security Vulnerabilities fixed in Firefox ESR 115.35.2 mfsa2026-42	May 7, 2026
mfsa2026-39	Security Vulnerabilities fixed in Thunderbird 140.10.1 mfsa2026-39	April 30, 2026
mfsa2026-38	Security Vulnerabilities fixed in Thunderbird 150.0.1 mfsa2026-38	April 30, 2026
mfsa2026-35	Security Vulnerabilities fixed in Firefox 150.0.1 mfsa2026-35	April 28, 2026
mfsa2026-37	Security Vulnerabilities fixed in Firefox ESR 115.35.1 mfsa2026-37	April 28, 2026

Known Exploited Mozilla Vulnerabilities

The following Mozilla vulnerabilities have been marked by CISA as Known to be Exploited by threat actors.

Title	Description	Added
Mozilla Multiple Products Remote Code Execution Vulnerability	Mozilla Firefox, SeaMonkey, and Thunderbird contain an unspecified vulnerability when JavaScript is enabled. This allows remote attackers to execute arbitrary code via vectors related to nsCSSFrameConstructor::ContentAppended, the appendChild method, incorrect index tracking, and the creation of multiple frames, which triggers memory corruption. CVE-2010-3765 Exploit Probability: 86.6%	October 6, 2025
Mozilla Firefox Use-After-Free Vulnerability	Mozilla Firefox and Firefox ESR contain a use-after-free vulnerability in Animation timelines that allows for code execution in the content process. CVE-2024-9680 Exploit Probability: 30.8%	October 15, 2024
Mozilla Firefox, Firefox ESR, and Thunderbird Use-After-Free Vulnerability	Mozilla Firefox, Firefox ESR, and Thunderbird contain a use-after-free vulnerability in SVG Animation, targeting Firefox and Tor browser users on Windows. CVE-2016-9079 Exploit Probability: 84.8%	June 22, 2023
Mozilla Firefox Security Feature Bypass Vulnerability	Moxilla Firefox allows remote attackers to bypass the Same Origin Policy to read arbitrary files or gain privileges. CVE-2015-4495 Exploit Probability: 71.6%	May 25, 2022
Mozilla Firefox and Thunderbird Type Confusion Vulnerability	Mozilla Firefox and Thunderbird contain a type confusion vulnerability that can occur when manipulating JavaScript objects due to issues in Array.pop, allowing for an exploitable crash. CVE-2019-11707 Exploit Probability: 84.3%	May 23, 2022
Mozilla Firefox and Thunderbird Sandbox Escape Vulnerability	Mozilla Firefox and Thunderbird contain a sandbox escape vulnerability that could result in remote code execution. CVE-2019-11708 Exploit Probability: 68.1%	May 23, 2022
Mozilla Firefox and Thunderbird Denial-of-Service Vulnerability	Mozilla Firefox and Thunderbird do not properly handle onreadystatechange events in conjunction with page reloading, which allows remote attackers to cause a denial-of-service or possibly execute arbitrary code via a crafted web site. CVE-2013-1690 Exploit Probability: 47.1%	March 28, 2022
Mozilla Firefox Use-After-Free Vulnerability	Mozilla Firefox contains a use-after-free vulnerability in WebGPU IPC Framework which can be exploited to perform arbitrary code execution. CVE-2022-26486 Exploit Probability: 5.5%	March 7, 2022
Mozilla Firefox Use-After-Free Vulnerability	Mozilla Firefox contains a use-after-free vulnerability in XSLT parameter processing which can be exploited to perform arbitrary code execution. CVE-2022-26485 Exploit Probability: 7.2%	March 7, 2022
Mozilla Firefox Information Disclosure Vulnerability	Mozilla Firefox does not properly initialize data structures for the nsDOMSVGZoomEvent::mPreviousScale and nsDOMSVGZoomEvent::mNewScale functions, which allows remote attackers to obtain sensitive information from process memory via a crafted web site. CVE-2013-1675 Exploit Probability: 7.9%	March 3, 2022
Mozilla Firefox 74 and Firefox ESR 68.6 nsDocShell vulnerability	A race condition can cause a use-after-free when running the nsDocShell destructor. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1. CVE-2020-6819 Exploit Probability: 0.4%	November 3, 2021
Mozilla Firefox 74 and Firefox ESR 68.6 ReadableStream vulnerability	A race condition can cause a use-after-free when handling a ReadableStream. This vulnerability affects Thunderbird < 68.7.0, Firefox < 74.0.1, and Firefox ESR < 68.6.1. CVE-2020-6820 Exploit Probability: 3.1%	November 3, 2021
Mozilla Firefox IonMonkey JIT compiler Type Confusion Vulnerability	Incorrect alias information in IonMonkey JIT compiler for setting array elements could lead to a type confusion. This vulnerability affects Firefox ESR < 68.4.1, Thunderbird < 68.4.1, and Firefox < 72.0.1 CVE-2019-17026 Exploit Probability: 59.1%	November 3, 2021

Of the known exploited vulnerabilities above, 3 are in the top 1%, or the 99th percentile of the EPSS exploit probability rankings. 5 known exploited Mozilla vulnerabilities are in the top 5% (95th percentile or greater) of the EPSS exploit probability rankings.

By the Year

In 2026 there have been 186 vulnerabilities in Mozilla with an average score of 8.2 out of ten. Last year, in 2025 Mozilla had 209 security vulnerabilities published. If vulnerabilities keep coming in at the current rate, it appears that number of security vulnerabilities in Mozilla in 2026 could surpass last years number. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.73.

Year	Vulnerabilities	Average Score
2026	186	8.19
2025	209	7.46
2024	204	7.10
2023	202	7.24
2022	188	7.42
2021	158	7.12
2020	184	7.25
2019	152	7.53
2018	345	7.65

It may take a day or so for new Mozilla vulnerabilities to show up in the stats or in the list of recent security vulnerabilities. Additionally vulnerabilities may be tagged under a different product or component name.

Recent Mozilla Security Vulnerabilities

CVE	Date	Vulnerability	Products
CVE-2026-8401	May 12, 2026	Firefox 150.0.3 Sandbox Escape in Profile Backup (Fixed) Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 150.0.3.	Firefox
CVE-2026-8391	May 12, 2026	JavaScript Engine flaw in Firefox 150.0.3 (fixed) Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150.0.3.	Firefox
CVE-2026-8390	May 12, 2026	Firefox WebAssembly Component UAF (pre-150.0.3) Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150.0.3.	Firefox
CVE-2026-8389	May 12, 2026	Firefox JIT Miscompilation in JS Engine, Fixed in 150.0.3 JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3.	Firefox
CVE-2026-8388	May 12, 2026	Firefox 150 JIT Boundary Condition Vulnerability in JS Engine Incorrect boundary conditions in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 150.0.3.	Firefox
CVE-2026-8094	May 07, 2026	Firefox ESR 140.10.2 WebRTC Vulnerability Other issue in the WebRTC component. This vulnerability was fixed in Firefox ESR 140.10.2 and Thunderbird 140.10.2.	Firefox Thunderbird
CVE-2026-8093	May 07, 2026	Firefox 150.0.1 Memcor bugs may allow arbitrary code execution Memory safety bugs present in Thunderbird 150.0.1. 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. This vulnerability was fixed in Firefox 150.0.2 and Thunderbird 150.0.2.	Firefox Thunderbird
CVE-2026-8092	May 07, 2026	Firefox 115.35.1/140.10.1/150.0.1 Memory Safety Bug Memory safety bugs present in Thunderbird ESR 140.10.1 and Thunderbird 150.0.1. 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. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR 140.10.2, Firefox ESR 115.35.2, Thunderbird 150.0.2, and Thunderbird 140.10.2.	Firefox Thunderbird
CVE-2026-8091	May 07, 2026	Firefox ESR AV Playback boundary flaw before 140.10.2 Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, Thunderbird 140.10.1, and Firefox ESR 115.35.2.	Firefox Thunderbird
CVE-2026-8090	May 07, 2026	Use-after-free in Firefox DOM Networking pre-150.0.2 Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR 140.10.2, Firefox ESR 115.35.2, Thunderbird 150.0.2, and Thunderbird 140.10.2.	Firefox Thunderbird
CVE-2026-7321	Apr 28, 2026	Firefox Sandbox Escape in WebRTC Networking before ESR 140.10.1 Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, Firefox ESR 140.10.1, and Thunderbird 140.10.1.	Firefox Thunderbird
CVE-2026-7324	Apr 28, 2026	Memory safety bugs in Firefox 150.0.0 (fixed 150.0.1) Memory safety bugs present in Thunderbird 150.0.0. 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. This vulnerability was fixed in Firefox 150.0.1 and Thunderbird 150.0.1.	Firefox Thunderbird
CVE-2026-7323	Apr 28, 2026	Memory Safety Bug in Firefox ESR 140.10.0 & Thunderbird 140.10.0 Memory safety bugs present in Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. 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. This vulnerability was fixed in Firefox 150.0.1, Firefox ESR 140.10.1, Thunderbird 150.0.1, and Thunderbird 140.10.1.	Firefox Thunderbird
CVE-2026-7322	Apr 28, 2026	Memory safety bugs in Firefox ESR 115.35.0/140.10.0 & 150.0.0 (fixed 150.0.1) Memory safety bugs present in Thunderbird ESR 140.10.0 and Thunderbird 150.0.0. 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. This vulnerability was fixed in Firefox 150.0.1, Firefox ESR 140.10.1, Firefox ESR 115.35.1, Thunderbird 150.0.1, and Thunderbird 140.10.1.	Firefox Thunderbird
CVE-2026-7320	Apr 28, 2026	Firefox Audio/Video Boundary Bug Info Disclosure (fixed in 150.0.1) Information disclosure due to incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 150.0.1, Firefox ESR 140.10.1, Firefox ESR 115.35.1, Thunderbird 150.0.1, and Thunderbird 140.10.1.	Firefox Thunderbird
CVE-2026-6786	Apr 21, 2026	Firefox 149 / ESR 140.9 Memory Safety Bugs (Arbitrary Code Exec) Memory safety bugs present in Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. 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. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6785	Apr 21, 2026	Mozilla Firefox Memory Safety Bug (ESR 115.34, 115.35, ESR 140.9/140.10, 149) Memory safety bugs present in Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird ESR 140.9, Firefox 149 and Thunderbird 149. 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. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6784	Apr 21, 2026	Memory Safety Bugs in Firefox 149 & Thunderbird 149 Memory safety bugs present in Firefox 149 and Thunderbird 149. 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. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6782	Apr 21, 2026	Info Disclosure via Firefox IP Protection Component Information disclosure in the IP Protection component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6783	Apr 21, 2026	Firefox 150 AV Playback CVE20266783 Integer Overflow Incorrect boundary conditions, integer overflow in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6781	Apr 21, 2026	DoS in Firefox AV Playback Component (CVE-2026-6781) Denial-of-service in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6780	Apr 21, 2026	Firefox A/V Playback DoS Vulnerability Denial-of-service in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6779	Apr 21, 2026	Mozilla Firefox JS Engine CVE-2026-6779 (Other issue) Other issue in the JavaScript Engine component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6778	Apr 21, 2026	Firefox 150 - Invalid Pointer in Audio/Video Playback Invalid pointer in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6777	Apr 21, 2026	CVE-2026-6777: Firefox DNS Component Vulnerability Other issue in the Networking: DNS component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6776	Apr 21, 2026	Firefox <150 WebRTC Networking boundary condition flaw (CVE-2026-6776) Incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6775	Apr 21, 2026	Firefox WebRTC Improper Boundary Check (CVE-2026-6775) Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6774	Apr 21, 2026	DOM Mitigation Bypass in Firefox Security Component Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6772	Apr 21, 2026	Firefox NSS Libraries Boundary Cond. before 150 Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6773	Apr 21, 2026	Firefox WebGPU Integer Overflow DoS Denial-of-service due to integer overflow in the Graphics: WebGPU component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6771	Apr 21, 2026	Firefox 150 DOM Mitigation Bypass in Security Component Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6770	Apr 21, 2026	IndexedDB flaw in Firefox <=150 (ESR 140.10) Other issue in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6769	Apr 21, 2026	Priv Escalation in Firefox Debugger (before 150) Privilege escalation in the Debugger component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6768	Apr 21, 2026	CVE-2026-6768: Mitigation Bypass in Firefox Cookies Handling Mitigation bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6767	Apr 21, 2026	NSS Lib Other Issue (Fixed in Firefox 150/ESR 115.35) Other issue in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6766	Apr 21, 2026	Firefox NSS boundary overflow (before 150/140.10) Incorrect boundary conditions in the Libraries component in NSS. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6765	Apr 21, 2026	Firefox Autofill Info Disclosure before 150 Information disclosure in the Form Autofill component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6764	Apr 21, 2026	Firefox DOM Boundary Condition Flaw in Device Interfaces (fixed in v150) Incorrect boundary conditions in the DOM: Device Interfaces component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6763	Apr 21, 2026	Firefox File Handling Mitigation Bypass (Before 150/ESR 140.10) Mitigation bypass in the File Handling component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6762	Apr 21, 2026	Firefox DOM Spoofing Vulnerability (pre-150) Core & HTML Spoofing issue in the DOM: Core & HTML component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6761	Apr 21, 2026	Firefox 150 PrivEsc via Networking Component Privilege escalation in the Networking component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6760	Apr 21, 2026	Firefox Networking Cookies Mitigation Bypass CVE-2026-6760 Mitigation bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6759	Apr 21, 2026	Use-after-free in Firefox Widget Cocoa (150) Use-after-free in the Widget: Cocoa component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6758	Apr 21, 2026	Use-after-free: WebAssembly Component in Firefox Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6757	Apr 21, 2026	Firefox WebAsm Null Pointer Bug Before v150 (CVE-2026-6757) Invalid pointer in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6756	Apr 21, 2026	Firefox for Android Mitigation Bypass Mitigation bypass in Firefox for Android. This vulnerability was fixed in Firefox 150.	Firefox
CVE-2026-6754	Apr 21, 2026	UAF in JavaScript Engine, fixed in Firefox 150/ESR 115.35/140.10 Use-after-free in the JavaScript Engine component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6755	Apr 21, 2026	Mozilla Firefox postMessage DOM Mitigation Bypass (CVE20266755) Mitigation bypass in the DOM: postMessage component. This vulnerability was fixed in Firefox 150 and Thunderbird 150.	Firefox Thunderbird
CVE-2026-6753	Apr 21, 2026	Firefox WebRTC Boundary Condition Vulnerability (fixed in 150/ESR 140.10) Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird
CVE-2026-6752	Apr 21, 2026	Firefox WebRTC Boundary Condition Flaw (before v150 / ESR 115.35) Incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.	Firefox Thunderbird