Mozilla Firefox Vulnerabilities

18 advisories affecting Mozilla Firefox

18

Total CVEs

16

Critical

2

High

CVE-2026-7321

Apr 28, 2026

Critical (9.6)

Sandbox escape due to incorrect boundary conditions in the WebRTC: Networking component. This vulnerability was fixed in Firefox 150, Thunderbird 150, and Firefox ESR 140.10.1....

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CVE-2026-6786

Apr 26, 2026

High (8.1)

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 ...

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CVE-2026-6785

Apr 26, 2026

High (8.1)

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...

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CVE-2026-6748

Apr 21, 2026

Critical (9.8)

Uninitialized memory in the Audio/Video: Web Codecs component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10....

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CVE-2026-6768

Apr 21, 2026

Critical (9.8)

Mitigation bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 150 and Thunderbird 150....

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CVE-2026-6771

Apr 21, 2026

Critical (9.8)

Mitigation bypass in the DOM: Security component. This vulnerability was fixed in Firefox 150, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10....

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CVE-2026-5731

Apr 7, 2026

Critical (9.8)

Memory safety bugs present in Firefox ESR 115.34.0, Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and w...

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CVE-2026-5735

Apr 7, 2026

Critical (9.8)

Memory safety bugs present in Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been expl...

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CVE-2026-5734

Apr 7, 2026

Critical (9.8)

Memory safety bugs present in Firefox ESR 140.9.0, Thunderbird ESR 140.9.0, Firefox 149.0.1 and Thunderbird 149.0.1. Some of these bugs showed evidence of memory corruption and we presume that with en...

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CVE-2026-4688

Mar 24, 2026

Critical (10.0)

Sandbox escape due to use-after-free in the Disability Access APIs component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4691

Mar 24, 2026

Critical (9.8)

Use-after-free in the CSS Parsing and Computation component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4696

Mar 24, 2026

Critical (9.8)

Use-after-free in the Layout: Text and Fonts component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4698

Mar 24, 2026

Critical (9.8)

JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 149, Firefox ESR < 115.34, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4700

Mar 24, 2026

Critical (9.8)

Mitigation bypass in the Networking: HTTP component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4701

Mar 24, 2026

Critical (9.8)

Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4702

Mar 24, 2026

Critical (9.8)

JIT miscompilation in the JavaScript Engine component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4705

Mar 24, 2026

Critical (9.8)

Undefined behavior in the WebRTC: Signaling component. This vulnerability affects Firefox < 149, Firefox ESR < 140.9, Thunderbird < 149, and Thunderbird < 140.9....

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CVE-2026-4725

Mar 24, 2026

Critical (10.0)

Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability affects Firefox < 149 and Thunderbird < 149....

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