Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 8.8 High.
Data as of 5 Nov 2026, 20:49 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 5 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Product Security Red Hat | Affected
| Fixed in
|
Description
Mozilla Firefox is an open-source web browser, designed for standards compliance, performance, and portability. Security Fix(es): * firefox: thunderbird: Privilege escalation in the DOM: Workers component (CVE-2026-16365) * firefox: thunderbird: Sandbox escape in the Remote Settings Client component (CVE-2026-75874) * firefox: Sandbox escape due to use-after-free in the DOM: Security component (CVE-2026-84121) * firefox: Internally found bugs fixed in Firefox 155, Firefox ESR 153.2, Firefox ESR 140.15 and Firefox ESR 115.40 (CVE-2026-84145) * firefox: Sandbox escape due to use-after-free in the DOM: Navigation component (CVE-2026-84119) * firefox: Use-after-free in the Audio/Video component (CVE-2026-84120) * firefox: Privilege escalation due to invalid pointer in the Graphics component (CVE-2026-84131) * firefox: Use-after-free in the DOM: Core & HTML component (CVE-2026-84124) * firefox: Use-after-free in the Audio/Video component (CVE-2026-84122) * firefox: Internally found bugs fixed in Firefox 155, Firefox ESR 153.2 and Firefox ESR 140.15 (CVE-2026-84143) For 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.
References
- access.redhat.com/errata/RHSA-2026:67129 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2503504 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2517832 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526753 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526760 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526764 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526765 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526767 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526773 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526778 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2526781 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_67129.json (opens in a new tab)