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CVE-2025-14321VulnerabilityPublished Updated

Red Hat Security Advisory: firefox security update

Affects Red Hat firefoxSource GCVE Database

0

Mentioned vulnerabilities

Authoritative record:CVE-2025-14321· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical : upgrade Red Hat firefox to 146.6 or 140.6 as a priority.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score
9.8Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 146.6, 140.6
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 9 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 146.6 or 140.6.

Affected software

ProductAffectedFixed in
Red Hat Product Security Red HatAffected
  • >=140.0 <140.6
  • >=146.0 <146.6
Fixed in
  • 140.6
  • 146.6

AI-suggested

Red Hat has released updated Firefox packages (Firefox ESR 140.6 and Firefox 146) that fix these vulnerabilities. Users of Red Hat Enterprise Linux 8.4 should apply these official updates promptly. For detailed update instructions, refer to Red Hat's advisory at https://access.redhat.com/articles/11258. No additional mitigation steps are indicated beyond applying the provided security update.

Description

Multiple security vulnerabilities affecting Mozilla Firefox and Thunderbird have been addressed in Red Hat Enterprise Linux 8.4 updates. These include memory safety bugs, use-after-free, JIT miscompilation, sandbox escape, privilege escalation, and same-origin policy bypass issues across various components such as WebRTC, JavaScript engine, graphics, netmonitor, request handling, and DOM notifications. The update fixes these issues in Firefox ESR 140.6 and Firefox 146 versions and is rated as important by Red Hat Product Security.

References

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