Mozilla: >> Firefox >> 143.0 Security Vulnerabilities
Memory safety bugs present in Firefox ESR 115.28, Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143. 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 affects Firefox < 144, Firefox ESR < 115.29, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.
CVSS Score
8.8
EPSS Score
0.001
Published
2025-10-14
Memory safety bugs present in Firefox ESR 140.3, Thunderbird ESR 140.3, Firefox 143 and Thunderbird 143. 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 affects Firefox < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.
CVSS Score
8.8
EPSS Score
0.001
Published
2025-10-14
Links in a sandboxed iframe could open an external app on Android without the required "allow-" permission. This vulnerability affects Firefox < 144 and Thunderbird < 144.
CVSS Score
6.5
EPSS Score
0.0
Published
2025-10-14
Use-after-free in MediaTrackGraphImpl::GetInstance() This vulnerability affects Firefox < 144, Firefox ESR < 140.4, Thunderbird < 144, and Thunderbird < 140.4.
CVSS Score
9.8
EPSS Score
0.001
Published
2025-10-14
Sandbox escape due to integer overflow in the Graphics: Canvas2D component. This vulnerability affects Firefox < 143.0.3.
CVSS Score
8.6
EPSS Score
0.001
Published
2025-09-30
JIT miscompilation in the JavaScript Engine: JIT component. This vulnerability affects Firefox < 143.0.3.
CVSS Score
7.5
EPSS Score
0.001
Published
2025-09-30
Sandbox escape due to use-after-free in the Graphics: Canvas2D component. This vulnerability affects Firefox < 143, Firefox ESR < 140.3, Thunderbird < 143, and Thunderbird < 140.3.
CVSS Score
7.1
EPSS Score
0.001
Published
2025-09-16
The HTTP/2 protocol does not consider the role of the TCP congestion window in providing information about content length, which makes it easier for remote attackers to obtain cleartext data by leveraging a web-browser configuration in which third-party cookies are sent, aka a "HEIST" attack.
CVSS Score
5.3
EPSS Score
0.023
Published
2016-09-06
The HTTPS protocol does not consider the role of the TCP congestion window in providing information about content length, which makes it easier for remote attackers to obtain cleartext data by leveraging a web-browser configuration in which third-party cookies are sent, aka a "HEIST" attack.
CVSS Score
5.3
EPSS Score
0.023
Published
2016-09-06
Cross-site scripting (XSS) vulnerability in clickstream.js in Y! Toolbar plugin for FireFox 3.1.0.20130813024103 for Mac, and 2.5.9.2013418100420 for Windows, allows remote attackers to inject arbitrary web script or HTML via a crafted URL that is stored by the victim.
CVSS Score
4.3
EPSS Score
0.003
Published
2014-01-26