{"id":"RLSA-2026:58899","summary":"Important: firefox security update","details":"Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability.\n\nSecurity Fix(es):\n\n* firefox: thunderbird: Mitigation bypass in the Data Loss Prevention component (CVE-2026-74983)\n\n* firefox: thunderbird: Site isolation issue in the Graphics: CanvasWebGL component (CVE-2026-74934)\n\n* firefox: thunderbird: Privilege escalation in the Networking: Cookies component (CVE-2026-74953)\n\n* firefox: thunderbird: Internally found bugs fixed in Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 (CVE-2026-74987)\n\n* firefox: thunderbird: Information disclosure in the Graphics component (CVE-2026-74948)\n\n* firefox: thunderbird: Use-after-free in the Graphics: ImageLib component (CVE-2026-74943)\n\n* firefox: thunderbird: Information disclosure in the DOM: UI Events & Focus Handling component (CVE-2026-74971)\n\n* firefox: thunderbird: Privilege escalation in the Graphics: CanvasWebGL component (CVE-2026-74941)\n\n* firefox: Privilege escalation in the Shell Integration component (CVE-2026-74965)\n\n* firefox: thunderbird: Privilege escalation due to incorrect boundary conditions in the Graphics: CanvasWebGL component (CVE-2026-74946)\n\n* firefox: Race condition, use-after-free in the Graphics component (CVE-2026-74973)\n\n* firefox: thunderbird: Privilege escalation due to use-after-free in the Graphics: Canvas2D component (CVE-2026-74949)\n\n* firefox: thunderbird: Internally found bugs fixed in Firefox ESR 115.39, Firefox ESR 140.14, Firefox ESR 153.1 and Firefox 154 (CVE-2026-74990)\n\n* firefox: thunderbird: Use-after-free in the JavaScript: WebAssembly component (CVE-2026-74936)\n\n* firefox: thunderbird: Use-after-free in the Graphics: Text component (CVE-2026-74940)\n\n* firefox: thunderbird: Site isolation issue in the WebExtensions component (CVE-2026-74960)\n\n* firefox: thunderbird: Use-after-free in the Layout: Text and Fonts component (CVE-2026-74969)\n\n* firefox: thunderbird: Mitigation bypass in the Storage: Cache API component (CVE-2026-74959)\n\n* firefox: thunderbird: JIT miscompilation in the JavaScript Engine: JIT component (CVE-2026-74976)\n\n* firefox: thunderbird: Same-origin policy bypass in the Graphics: ImageLib component (CVE-2026-74974)\n\n* firefox: thunderbird: Mitigation bypass in the Safe Browsing component (CVE-2026-74957)\n\n* firefox: thunderbird: Same-origin policy bypass in the Audio/Video: Playback component (CVE-2026-74967)\n\n* firefox: Privilege escalation in the Remote Settings Client component (CVE-2026-74942)\n\n* firefox: thunderbird: Privilege escalation in the DOM: Navigation component (CVE-2026-74939)\n\n* firefox: thunderbird: Information disclosure in the DOM: Push Subscriptions component (CVE-2026-74972)\n\n* firefox: thunderbird: Information disclosure in the Graphics: Text component (CVE-2026-74945)\n\n* firefox: thunderbird: Same-origin policy bypass in the Networking: Cookies component (CVE-2026-74963)\n\n* firefox: thunderbird: Use-after-free in the DOM: Core & HTML component (CVE-2026-74944)\n\n* firefox: Integer overflow in the Graphics component (CVE-2026-74964)\n\n* firefox: Site isolation issue in the Networking: Cookies component (CVE-2026-74962)\n\n* firefox: thunderbird: Privilege escalation in the DOM: Networking component (CVE-2026-74935)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.","modified":"2026-08-26T01:11:14.939732833Z","published":"2026-08-25T12:07:46.973584Z","upstream":["CVE-2026-74934","CVE-2026-74935","CVE-2026-74936","CVE-2026-74939","CVE-2026-74940","CVE-2026-74941","CVE-2026-74942","CVE-2026-74943","CVE-2026-74944","CVE-2026-74945","CVE-2026-74946","CVE-2026-74948","CVE-2026-74949","CVE-2026-74953","CVE-2026-74957","CVE-2026-74959","CVE-2026-74960","CVE-2026-74962","CVE-2026-74963","CVE-2026-74964","CVE-2026-74965","CVE-2026-74967","CVE-2026-74969","CVE-2026-74971","CVE-2026-74972","CVE-2026-74973","CVE-2026-74974","CVE-2026-74976","CVE-2026-74983","CVE-2026-74987","CVE-2026-74990"],"database_specific":{"license":"CC-BY-4.0","license_url":"https://creativecommons.org/licenses/by/4.0/","source_advisory":"RHSA-2026:58899"},"references":[{"type":"ADVISORY","url":"https://errata.rockylinux.org/RLSA-2026:58899"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517866"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517874"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517834"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517845"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517859"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517825"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517849"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517840"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517831"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517820"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517826"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517846"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517836"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517841"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517863"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517872"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517833"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517868"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517823"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517853"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517822"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517870"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517819"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517862"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517851"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517839"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517860"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517856"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517837"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517858"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2517835"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:58899"}],"affected":[{"package":{"name":"firefox","ecosystem":"Rocky Linux:10","purl":"pkg:rpm/rocky-linux/firefox?distro=rocky-linux-10&epoch=0"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:140.14.0-1.el10_2"}],"database_specific":{"yum_repository":"AppStream"}}],"database_specific":{"source":"https://storage.googleapis.com/resf-osv-data/RLSA-2026:58899.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H"}],"credits":[{"name":"Rocky Enterprise Software Foundation"},{"name":"Red Hat"}]}