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Products by Mozilla Sorted by Most Security Vulnerabilities since 2018

Mozilla Firefox2466 vulnerabilities
Open source web browser

Mozilla Thunderbird1686 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 Focus24 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
mfsa2026-107	Security Vulnerabilities fixed in Firefox ESR 115.43 mfsa2026-107	October 13, 2026
mfsa2026-106	Security Vulnerabilities fixed in Firefox 158 mfsa2026-106	October 13, 2026
mfsa2026-108	Security Vulnerabilities fixed in Firefox ESR 153.5 mfsa2026-108	October 13, 2026
mfsa2026-110	Security Vulnerabilities fixed in Thunderbird 153.5 mfsa2026-110	October 13, 2026
mfsa2026-109	Security Vulnerabilities fixed in Thunderbird 158 mfsa2026-109	October 13, 2026
mfsa2026-104	Security Vulnerabilities fixed in Firefox 157.0.1 mfsa2026-104	October 6, 2026
mfsa2026-105	Security Vulnerabilities fixed in Firefox for iOS 157.1 mfsa2026-105	October 5, 2026
mfsa2026-101	Security Vulnerabilities fixed in Thunderbird 157 mfsa2026-101	September 30, 2026
mfsa2026-103	Security Vulnerabilities fixed in Thunderbird 153.4 mfsa2026-103	September 30, 2026
mfsa2026-102	Security Vulnerabilities fixed in Thunderbird 140.17 mfsa2026-102	September 30, 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: 83.2%	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: 23.2%	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: 87.5%	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: 68.6%	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: 37.7%	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: 55.9%	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: 69.0%	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: 2.4%	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: 14.3%	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: 6.7%	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: 3.0%	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: 7.1%	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: 46.3%	November 3, 2021

Of the known exploited vulnerabilities above, 5 are in the top 1%, or the 99th percentile of the EPSS exploit probability rankings. 4 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 514 vulnerabilities in Mozilla with an average score of 7.9 out of ten. Last year, in 2025 Mozilla had 209 security vulnerabilities published. That is, 305 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.42.

Year	Vulnerabilities	Average Score
2026	514	7.88
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	7.52
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-2026-96869	Sep 29, 2026	Firefox Networking Component Info Disclosure (pre-140.17/153.4/157) Information disclosure in the Networking component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.	Firefox Thunderbird
CVE-2026-92240	Sep 15, 2026	Thunderbird <140.16 OOB Read in IMAP Parser via * ID Response A malicious or compromised IMAP server can trigger an out-of-bounds read in the IMAP response parser by sending an untagged '* ID' response, crashing Thunderbird. The affected parsing path is reachable before authentication. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.	Thunderbird
CVE-2026-92239	Sep 15, 2026	OOB buffer read in Thunderbird IMAP parser before 140.16 A maliciously constructed IMAP line could cause an out-of-bounds buffer read. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.	Thunderbird
CVE-2026-92238	Sep 15, 2026	Memory Safety Violation via Malformed Mail Header in Thunderbird <140.16 A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.	Thunderbird
CVE-2026-92079	Sep 15, 2026	Widget: Win32 Mitigation Bypass in Firefox 156 ESR 153.3 Mitigation bypass in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92078	Sep 15, 2026	Firefox Denial-of-service in Security component before 156 Denial-of-service in the Security component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92077	Sep 15, 2026	DoS in Firefox SVG component before v156 Denial-of-service in the SVG component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92076	Sep 15, 2026	Firefox 156+ Boundary Condition Flaw in Networking Component Incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92075	Sep 15, 2026	Mitigation bypass in Firefox Networking component pre-156/ESR153.3 Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92074	Sep 15, 2026	Mitigation Bypass in Firefox Popup Blocker (before 156) Mitigation bypass in the Popup Blocker component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92073	Sep 15, 2026	Firefox: PrivEsc via Enterprise Policies pre-156/153.3 Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92072	Sep 15, 2026	Firefox SB boundary issue fixed in v156/ESR153.3 Incorrect boundary conditions in the Safe Browsing component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92071	Sep 15, 2026	Firefox Sandbox Escape via Widget Boundaries fixed in v156/ESR 153.3 Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92070	Sep 15, 2026	Firefox Info Disclosure in Networking Comp (before 156/ESR 153.3) Information disclosure in the Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92069	Sep 15, 2026	Firefox Navigation Component Spoofing (fixed in 156) Spoofing issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92068	Sep 15, 2026	Site isolation flaw in Firefox Reader Mode (pre156/ESR153.3) Site isolation issue in the Reader Mode component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92067	Sep 15, 2026	Use-after-free in Gtk Widget for Firefox/Thunderbird <156 Use-after-free in the Widget: Gtk component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92066	Sep 15, 2026	Sandbox escape in Firefox/Thunderbird Profile Backup Sandbox escape in the Profile Backup component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92065	Sep 15, 2026	Firefox sandbox escape in Win32 Widget before v156 Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92064	Sep 15, 2026	CVE-2026-92064: Win32 Widget Sandbox Esc. in Firefox<156, Thunderbird<156 Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92063	Sep 15, 2026	DoS in Audio/Video component of Firefox & Thunderbird Denial-of-service in the Audio/Video component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92062	Sep 15, 2026	Privilege escalation via Session Restore in Firefox/Thunderbird before 156/153.3 Privilege escalation in the Session Restore component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92061	Sep 15, 2026	Incorrect boundary conditions in Process Sandboxing (Firefox/Thunderbird) Incorrect boundary conditions in the Security: Process Sandboxing component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92060	Sep 15, 2026	Use-After-Free in Firefox/Thunderbird i18n before v156 Use-after-free in the Internationalization component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92059	Sep 15, 2026	Mozilla Firefox 156 DOM Boundary Condition Vulnerability in Editor Incorrect boundary conditions in the DOM: Editor component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92058	Sep 15, 2026	Firefox Graphics UA-FREE before v156 Use-after-free in the Graphics component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92057	Sep 15, 2026	Mitigation Bypass in Firefox Enterprise Policies (v156) Mitigation bypass in the Enterprise Policies component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92056	Sep 15, 2026	Use-after-free in Firefox Text component (pre-156) Use-after-free in the Graphics: Text component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92055	Sep 15, 2026	Privilege Escalation in DevTools (Firefox/Thunderbird) < v156 Privilege escalation in the DevTools component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92054	Sep 15, 2026	Privilege Escalation in Firefox Memory Component (before 156) Privilege escalation in the Memory component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92053	Sep 15, 2026	Privilege Escalation in CanvasWebGL (Firefox <156/Thunderbird <156) Privilege escalation in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92052	Sep 15, 2026	Firefox CanvasWebGL PrivEsc via Uninit Mem (Pre-156) Privilege escalation due to uninitialized memory in the Graphics: CanvasWebGL component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92051	Sep 15, 2026	Graphics Pointer Spoofing in Mozilla Firefox & Thunderbird Spoofing issue due to invalid pointer in the Graphics component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92050	Sep 15, 2026	XPConnect Race Condition Sandbox Escape in Firefox/Thunderbird Sandbox escape due to race condition in the XPConnect component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92049	Sep 15, 2026	UAF in Firefox Widget (Win32) before 156 Use-after-free in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92048	Sep 15, 2026	Firefox/Thunderbird Sandbox Escape via Widget Win32 Boundary (pre-156/153.3) Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92047	Sep 15, 2026	Privilege Escalation in CR component before Firefox 156 Privilege escalation in the Crash Reporting component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92046	Sep 15, 2026	Use-after-free in Firefox Graphics before v156 Use-after-free in the Graphics component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92045	Sep 15, 2026	Firefox 156 Sandbox Escape in WebRTC Component Sandbox escape due to incorrect boundary conditions in the WebRTC component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92044	Sep 15, 2026	Mozilla Firefox 156 Info Disclosure in Networking:HTTP Component Information disclosure in the Networking: HTTP component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92043	Sep 15, 2026	Privilege Escalation: Audio/Video Boundary Bug in Firefox<156 & Thunderbird<156 Privilege escalation due to incorrect boundary conditions in the Audio/Video component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92042	Sep 15, 2026	DOM Content Processes Race Cond. pre-156 Firefox/ESR 153.3 Race condition in the DOM: Content Processes component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92041	Sep 15, 2026	Mitigation Bypass in Firefox/Thunderbird DOM Networking (156/ESR153.3) Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92040	Sep 15, 2026	Use-After-Free in JS WebAssembly (Firefox & Thunderbird) Use-after-free in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92039	Sep 15, 2026	Mitigation Bypass in Mozilla Firefox 156 Notifications DOM Component Mitigation bypass in the DOM: Notifications component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92038	Sep 15, 2026	Mitigation Bypass in Remote Settings Client (FF 156, ESR 153.3, Thunderbird 156) Mitigation bypass in the Remote Settings Client component. This vulnerability was fixed in Firefox 156, Firefox ESR 153.3, Thunderbird 156, and Thunderbird 153.3.	Firefox Thunderbird
CVE-2026-92037	Sep 15, 2026	Mozilla Firefox/Thunderbird DOM Animation Boundary Condition Flaw Incorrect boundary conditions in the DOM: Animation component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92036	Sep 15, 2026	Firefox/Thunderbird 156 Boundary Error in Net:HTTP Component Incorrect boundary conditions in the Networking: HTTP component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird
CVE-2026-92035	Sep 15, 2026	Sandbox escape: Graphics boundary bug in Thunderbird/Firefox <140.17/156 Sandbox escape due to incorrect boundary conditions in the Graphics component. This vulnerability was fixed in Thunderbird 140.17, Firefox 156, Firefox ESR 153.3, Thunderbird 156, Thunderbird 153.3, Firefox ESR 115.42, and Firefox ESR 140.17.	Firefox Thunderbird
CVE-2026-92034	Sep 15, 2026	Site Isolation Flaw in Firefox & Thunderbird Graphics Component Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 156 and Thunderbird 156.	Firefox Thunderbird