Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High.
Data as of 26 Oct 2026, 09:15 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 31% 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:N/I:H/A:NExploitation 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 Hat Product Security Red Hat | Affected
| Fixed in– |
AI-suggested
Red Hat has released updated Firefox and Thunderbird packages for Red Hat Enterprise Linux 8.4 (including AUS and EUS extensions) that address these vulnerabilities. Users should apply the security update (firefox-140.7.0-1.el8_4) as soon as possible following Red Hat's update instructions at https://access.redhat.com/articles/11258. This update fixes all listed CVEs and mitigates the associated risks. No additional mitigation actions are specified or required beyond applying the official update.
Description
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in Red Hat Enterprise Linux 8.4 updates. These include spoofing, use-after-free, memory safety bugs, sandbox escapes, information disclosure, mitigation bypass, and clickjacking issues across various components such as Downloads Panel, JavaScript engine, Graphics, IPC, Networking, DOM, and PDF Viewer. The update fixes these issues in Firefox ESR 140.7, Thunderbird ESR 140.7, Firefox 147, and Thunderbird 147.
References
- access.redhat.com/errata/RHSA-2026:2073 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420507 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428961 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428963 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428965 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428966 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428967 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428968 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428969 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428971 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428972 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428973 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428975 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2428978 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_2073.json (opens in a new tab)