Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 5 Nov 2026, 23:05 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 16 Feb 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
AI-suggested
Red Hat has released security updates for affected versions of Firefox and Thunderbird on Red Hat Enterprise Linux 8.4. Users and administrators should apply these updates promptly following Red Hat's published instructions at https://access.redhat.com/articles/11258. Since official fixes are available, applying the vendor-provided patches is the recommended mitigation. No additional or alternative mitigations are indicated in the advisory.
Description
Multiple security vulnerabilities affecting Mozilla Firefox and related components have been addressed in a Red Hat security update. These include heap buffer overflows, use-after-free conditions, integer overflows, sandbox escapes, privilege escalations, mitigation bypasses, information disclosure, and same-origin policy bypasses. The fixes apply to Firefox ESR 115.33, ESR 140.8, Firefox 148, Thunderbird ESR 140.8, and Thunderbird 148. The update is rated as important by Red Hat Product Security.
References
- access.redhat.com/errata/RHSA-2026:3491 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2440219 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442284 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442287 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442288 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442290 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442291 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442292 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442294 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442295 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442297 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442298 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442300 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442302 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442304 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442307 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442308 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442309 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2442312 (opens in a new tab)