Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Not known to be exploited · CVSS 7.5 High · fixed in Red Hat package updates : patch Red Hat firefox 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
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 an official security update for Firefox ESR 140.7 and Thunderbird ESR 140.7 as part of Red Hat Enterprise Linux 7 Extended Lifecycle Support. Users should apply the update promptly to remediate these vulnerabilities. Detailed update instructions are available at https://access.redhat.com/articles/11258. Since this is an official fix, applying the update is the recommended mitigation.
Description
Multiple security vulnerabilities have been identified and fixed in Mozilla Firefox and Thunderbird as part of a Red Hat Enterprise Linux 7 Extended Lifecycle Support update. These include spoofing, use-after-free, memory safety bugs, sandbox escapes, information disclosure, mitigation bypass, and clickjacking issues affecting various components such as Downloads Panel, JavaScript engine, Graphics, IPC, Networking, DOM, and PDF Viewer. The update addresses these issues in Firefox ESR 140.7 and Thunderbird ESR 140.7, as well as Firefox 147 and Thunderbird 147.
References
- access.redhat.com/errata/RHSA-2026:2231 (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_2231.json (opens in a new tab)