Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 7.5 High · patch available : patch Red Hat firefox soon.
Data as of 6 Nov 2026, 01:06 UTC
- Patch
- Available
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 28 Apr 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
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 (Firefox ESR 140.10.1 and 150.0.1, Thunderbird ESR 140.10.1 and 150.0.1) that fix these vulnerabilities. Users of affected Red Hat Enterprise Linux 9.0 systems should apply these official updates promptly. Detailed update instructions are available at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated by the vendor advisory.
Description
Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in Red Hat Enterprise Linux 9.0 updates. These include memory safety bugs, information disclosure due to incorrect boundary conditions in the Audio/Video component, and a sandbox escape vulnerability in the WebRTC networking component. The update fixes these issues in Firefox ESR 140.10.1 and Firefox 150.0.1, as well as Thunderbird ESR 140.10.1 and Thunderbird 150.0.1.
References
- access.redhat.com/errata/RHSA-2026:21743 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2463481 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2463483 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2463484 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2463485 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_21743.json (opens in a new tab)