Mozilla: >> Firefox Security Vulnerabilities
Memory safety bugs present in Firefox 139 and Thunderbird 139. 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 < 140 and Thunderbird < 140.
CVSS Score
8.1
EPSS Score
0.001
Published
2025-06-24
A use-after-free in FontFaceSet resulted in a potentially exploitable crash. This vulnerability affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
CVSS Score
9.8
EPSS Score
0.001
Published
2025-06-24
An attacker who enumerated resources from the WebCompat extension could have obtained a persistent UUID that identified the browser, and persisted between containers and normal/private browsing mode, but not profiles. This vulnerability affects Firefox < 140, Firefox ESR < 115.25, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
CVSS Score
4.3
EPSS Score
0.001
Published
2025-06-24
The executable file warning did not warn users before opening files with the `terminal` extension.
*This bug only affects Firefox for macOS. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
CVSS Score
8.8
EPSS Score
0.0
Published
2025-06-24
An attacker was able to bypass the `connect-src` directive of a Content Security Policy by manipulating subdocuments. This would have also hidden the connections from the Network tab in Devtools. This vulnerability affects Firefox < 140 and Thunderbird < 140.
CVSS Score
9.1
EPSS Score
0.001
Published
2025-06-24
When a URL was provided in a link querystring parameter, Firefox for Android would follow that URL instead of the correct URL, potentially leading to phishing attacks.
*This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 140.
CVSS Score
4.3
EPSS Score
0.0
Published
2025-06-24
Firefox could have incorrectly parsed a URL and rewritten it to the youtube.com domain when parsing the URL specified in an `embed` tag. This could have bypassed website security checks that restricted which domains users were allowed to embed. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
CVSS Score
6.5
EPSS Score
0.001
Published
2025-06-24
When a file download is specified via the `Content-Disposition` header, that directive would be ignored if the file was included via a `<embed>` or `<object>` tag, potentially making a website vulnerable to a cross-site scripting attack. This vulnerability affects Firefox < 140, Firefox ESR < 128.12, Thunderbird < 140, and Thunderbird < 128.12.
CVSS Score
6.1
EPSS Score
0.001
Published
2025-06-24
An integer overflow was present in `OrderedHashTable` used by the JavaScript engine This vulnerability affects Firefox < 139.0.4.
CVSS Score
9.8
EPSS Score
0.001
Published
2025-06-11
Certain canvas operations could have lead to memory corruption. This vulnerability affects Firefox < 139.0.4.
CVSS Score
9.8
EPSS Score
0.001
Published
2025-06-11