Mozilla: >> Firefox >> 56.0 Security Vulnerabilities
Mitigation bypass in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
9.1
EPSS Score
0.003
Published
2026-07-21
Privilege escalation in the DOM: Workers component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
8.8
EPSS Score
0.003
Published
2026-07-21
Privilege escalation in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
8.8
EPSS Score
0.003
Published
2026-07-21
Sandbox escape due to invalid pointer in the Disability Access APIs component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
10.0
EPSS Score
0.004
Published
2026-07-21
Incorrect boundary conditions in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
9.1
EPSS Score
0.003
Published
2026-07-21
Memory safety bugs present in Firefox 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.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-05-07
Undefined behavior in the Audio/Video component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.
CVSS Score
9.1
EPSS Score
0.003
Published
2026-03-24
Spoofing issue in the Privacy: Anti-Tracking component. This vulnerability was fixed in Firefox 149 and Thunderbird 149.
CVSS Score
6.5
EPSS Score
0.002
Published
2026-03-24
Undefined behavior in the WebRTC: Signaling component. This vulnerability was fixed in Firefox 149, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
CVSS Score
8.1
EPSS Score
0.003
Published
2026-03-24
When switching between Android apps using the card carousel Firefox shows a black screen as its card image when a password-related screen was the last one being used. Prior to Firefox 144 the password edit screen was visible. This vulnerability was fixed in Firefox 144.
CVSS Score
9.1
EPSS Score
0.003
Published
2025-10-14