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, 21:47 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 updated Firefox packages for Red Hat Enterprise Linux 8.8 variants that address these vulnerabilities. Users should apply these official updates promptly to remediate the security issues. Detailed update instructions are available in the Red Hat advisory and knowledge base article. No additional mitigation steps are indicated beyond applying the provided patches.
Description
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in a Red Hat security update. These include privilege escalation, sandbox escapes, and use-after-free bugs in various components such as DOM, Audio/Video, Graphics, and Remote Settings Client. The update fixes these issues in Firefox 155, Firefox ESR 153.2, Firefox ESR 140.15, and Firefox ESR 115.40. The vulnerabilities have been rated as having an important security impact by Red Hat.
References
- access.redhat.com/errata/RHSA-2026:76746 (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_76746.json (opens in a new tab)