Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.8 Critical.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Red Hatredhat/firefoxpkg:rpm/redhat/firefoxOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released official patches for these vulnerabilities in Firefox ESR 140.6 and Firefox 146 packages for Red Hat Enterprise Linux 9.2 across multiple architectures. Users and administrators should apply the updates provided by Red Hat promptly to remediate these security issues. For detailed update instructions, refer to Red Hat's advisory at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the official patches.
Description
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in Red Hat Enterprise Linux 9.2 updates. These vulnerabilities include memory safety bugs, use-after-free, JIT miscompilation, sandbox escape, privilege escalation, and same-origin policy bypass issues across various components such as WebRTC, JavaScript engine, graphics, netmonitor, request handling, and DOM notifications. The update fixes these issues in Firefox ESR 140.6 and Firefox 146 versions. Red Hat has released patches for these vulnerabilities in their Firefox packages for multiple architectures.
References
- access.redhat.com/errata/RHSA-2026:0017 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420502 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420503 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420504 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420506 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420508 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420509 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420512 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420513 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420516 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420517 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_0017.json (opens in a new tab)