Red Hat Security Advisory: firefox security update
Affects Red Hat firefoxSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 6.5 Medium.
Data as of 5 Nov 2026, 19:02 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:LExploitation evidence
Disclosed: evidence found.
CVE published 1 Apr 2025
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
AI-suggested
Red Hat has released updated Firefox packages (version 128.9.0-2.el9_2) for Red Hat Enterprise Linux 9.2 Extended Update Support and related variants. Users and administrators should apply these official updates promptly to remediate the vulnerabilities. For detailed update instructions, refer to the Red Hat article at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated by the vendor advisory.
Description
Red Hat has issued a security advisory for Firefox addressing multiple vulnerabilities including URL bar spoofing via non-BMP Unicode characters, a use-after-free triggered by XSLTProcessor, and various memory safety bugs. These issues affect Firefox and Thunderbird versions 137 and ESR 128.9 series. The update is rated as Important by Red Hat and fixes are included in Firefox 128.9.0-2.el9_2 packages for Red Hat Enterprise Linux 9.2 Extended Update Support and related variants.
References
- access.redhat.com/errata/RHSA-2025:3589 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2356556 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2356562 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2356563 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2025/rhsa-2025_3589.json (opens in a new tab)