Mozilla: >> Firefox >> 101 Security Vulnerabilities
Privilege escalation in the WebDriver BiDi component. This vulnerability was fixed in Firefox 155 and Thunderbird 155.
CVSS Score
8.8
EPSS Score
0.002
Published
2026-09-01
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
CVSS Score
9.8
EPSS Score
0.002
Published
2026-09-01
Use-after-free in the JavaScript: GC component. This vulnerability was fixed in Firefox 155, Firefox ESR 153.2, Thunderbird 155, and Thunderbird 153.2.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-09-01
Sandbox escape due to use-after-free in the DOM: Navigation component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
CVSS Score
9.6
EPSS Score
0.003
Published
2026-09-01
Use-after-free in the Audio/Video component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
CVSS Score
5.4
EPSS Score
0.002
Published
2026-09-01
Sandbox escape due to use-after-free in the DOM: Security component. This vulnerability was fixed in Firefox 155, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.
CVSS Score
9.6
EPSS Score
0.003
Published
2026-09-01
Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154, Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and Thunderbird 153.2.
CVSS Score
10.0
EPSS Score
0.004
Published
2026-08-18
Privilege escalation in the Enterprise Policies component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-08-18
Site isolation issue in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 154, Firefox ESR 153.1, Thunderbird 154, and Thunderbird 153.1.
CVSS Score
9.1
EPSS Score
0.003
Published
2026-08-18
Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
CVSS Score
9.8
EPSS Score
0.005
Published
2026-08-18