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
A security update for Firefox is available for Red Hat Enterprise Linux 9.2 and related SAP solutions. Users should apply the Firefox update packages (version 140.15.0-1.el9_2) provided by Red Hat to remediate these vulnerabilities. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the official update.
Description
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in a Red Hat security update for Red Hat Enterprise Linux 9.2. 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 and ESR versions 153.2, 140.15, and 115.40.
References
- access.redhat.com/errata/RHSA-2026:76742 (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_76742.json (opens in a new tab)