Security Vulnerabilities fixed in Firefox ESR 115.16 — Mozilla

A compromised content process could have allowed for the arbitrary loading of cross-origin pages.
An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the resource://pdf.js origin. This could allow them to access cross-origin PDF content. This access is limited to “same site” documents by the Site Isolation feature on desktop clients, but full cross-origin access is possible on Android versions.
An attacker could, via a specially crafted multipart response, execute arbitrary JavaScript under the resource://devtools origin. This could allow them to access cross-origin JSON content. This access is limited to “same site” documents by the Site Isolation feature on desktop clients, but full cross-origin access is possible on Android versions.
Memory safety bugs present in Firefox 130, Firefox ESR 115.15, Firefox ESR 128.2, and Thunderbird 128.2. 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.