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, 21:04 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
|
AI-suggested
Red Hat has released security updates for Firefox in Red Hat Enterprise Linux 7 Extended Lifecycle Support. Users should apply these official updates to remediate the vulnerabilities. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigation is required beyond applying the provided patches.
Description
Multiple security vulnerabilities have been identified and fixed in Mozilla Firefox and Thunderbird, including privilege escalation, sandbox escape, and use-after-free bugs affecting various components such as DOM, Audio/Video, Graphics, and Remote Settings Client. These issues were addressed in Firefox 155 and several Extended Support Release (ESR) versions. The update is rated as important by Red Hat and affects Red Hat Enterprise Linux 7 Extended Lifecycle Support versions.
References
- access.redhat.com/errata/RHSA-2026:76741 (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_76741.json (opens in a new tab)