Mozilla: >> Firefox >> 39.0.3 Security Vulnerabilities
Mitigation bypass in the Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
9.1
EPSS Score
0.002
Published
2026-07-21
Mitigation bypass in the DOM: Service Workers component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-21
Integer overflow in the Audio/Video: Playback component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-21
Invalid pointer in the Security: PSM component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
7.5
EPSS Score
0.003
Published
2026-07-21
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-21
Memory safety bugs present in Firefox 152. 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 153 and Thunderbird 153.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-21
Memory safety bugs present in Firefox ESR 140.12 and Firefox 152. 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 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
CVSS Score
9.8
EPSS Score
0.003
Published
2026-07-21
Site isolation issue in the Graphics component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-07-21
Site isolation issue in the DOM: Navigation component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
7.5
EPSS Score
0.001
Published
2026-07-21
Information disclosure in the DOM: Security component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
CVSS Score
7.5
EPSS Score
0.002
Published
2026-07-21
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