Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High : upgrade Red Hat firefox to 140.7.0 soon.
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.
- Patch
- Available – fixed in 140.7.0
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
Upgrade Red Hat firefox to 140.7.0.
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 8.2 AUS that address these vulnerabilities. Users should apply the security update as detailed in Red Hat advisory RHSA-2026:2074 and the linked article https://access.redhat.com/articles/11258. This update fixes the listed CVEs and mitigates the associated risks. No additional vendor-recommended mitigations or workarounds are indicated.
Description
A security update for Mozilla Firefox distributed by Red Hat addresses multiple vulnerabilities including spoofing, use-after-free, sandbox escape, information disclosure, mitigation bypass, and clickjacking issues. These vulnerabilities affect Firefox ESR 140.7 and Firefox 147 versions, as well as Thunderbird ESR 140.7 and Thunderbird 147. The update fixes issues in various components such as Downloads Panel, JavaScript engine, Graphics, IPC, Networking, DOM security, and PDF Viewer. The update is rated as important by Red Hat Product Security.
References
- access.redhat.com/errata/RHSA-2026:2074 (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_2074.json (opens in a new tab)