Affected: Mozilla Firefox, Mozilla Thunderbird

Memory safety bugs present in Firefox 134, Thunderbird 134, Firefox ESR 128.6, and Thunderbird 128.6. 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 135, Firefox ESR 128.7, Thunderbird 128.7, and Thunderbird 135.

Affected: Ubuntu:20.04:LTS: firefox

Multiple security issues were discovered in Firefox. If a user were tricked into opening a specially crafted website, an attacker could potentially exploit these to cause a denial of service, obtain sensitive information across domains, or execute arbitrary code. (CVE-2025-1011, CVE-2025-1013, CVE-2025-1014, CVE-2025-1016, CVE-2025-1017, CVE-2025-1018, CVE-2025-1019, CVE-2025-1020)

Ivan Fratric discovered that Firefox did not properly handle XSLT data, leading to a use-after-free vulnerability. An attacker could potentially exploit this issue to cause a denial of service, or execute arbitrary code. (CVE-2025-1009)

Atte Kettunen discovered that Firefox did not properly manage memory in the Custom Highlight API, leading to a use-after-free vulnerability. An attacker could potentially exploit this issue to cause a denial of service, or execute arbitrary code. (CVE-2025-1010)

Nils Bars discovered that Firefox did not properly manage memory during concurrent delazification, leading to a use-after-free vulnerability. An attacker could potentially exploit this issue to cause a denial of service, or execute arbitrary code. (CVE-2025-1012)