Skip to main content
CVE-2025-14321VulnerabilityPublished Updated

Red Hat Security Advisory: thunderbird security update

Affects Red Hat thunderbirdSource GCVE Database

0

Mentioned vulnerabilities

Authoritative record:CVE-2025-14321· Critical 9.8

Not known to be exploited · CVSS 9.8 Critical : upgrade the Red Hat redhat/thunderbird package to 146.1 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 146.1, 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 the Red Hat redhat/thunderbird package to 146.1 or 140.6.

Affected software

ProductAffectedFixed in
Red Hatredhat/thunderbirdpkg:rpm/redhat/thunderbirdOther threatsAffected
  • >=140.0 <140.6
  • >=146 <146.1
Fixed in
  • 140.6
  • 146.1

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Red Hat has released updated Thunderbird packages (version 140.6.0-1.el9_6) for Red Hat Enterprise Linux 9.6 Extended Update Support and related variants that address these vulnerabilities. Users should apply these official security updates promptly to remediate the issues. For detailed update instructions, refer to Red Hat's advisory and update article at https://access.redhat.com/articles/11258. Since the advisory provides an official fix, applying the update is the recommended mitigation. No additional vendor-recommended mitigations are indicated.

Description

This update for MozillaThunderbird fixes the following issues: Changes in MozillaThunderbird: - Mozilla Thunderbird 140.6.0 ESR MFSA 2025-96 (bsc#1254551) * CVE-2025-14321 (bmo#1992760) Use-after-free in the WebRTC: Signaling component * CVE-2025-14322 (bmo#1996473) Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL component * CVE-2025-14323 (bmo#1996555) Privilege escalation in the DOM: Notifications component * CVE-2025-14324 (bmo#1996840) JIT miscompilation in the JavaScript Engine: JIT component * CVE-2025-14325 (bmo#1998050) JIT miscompilation in the JavaScript Engine: JIT component * CVE-2025-14328 (bmo#1996761) Privilege escalation in the Netmonitor component * CVE-2025-14329 (bmo#1997018) Privilege escalation in the Netmonitor component * CVE-2025-14330 (bmo#1997503) JIT miscompilation in the JavaScript Engine: JIT component * CVE-2025-14331 (bmo#2000218) Same-origin policy bypass in the Request Handling component * CVE-2025-14333 (bmo#1966501, bmo#1997639) Memory safety bugs fixed in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146

References

Community reviews

Loading reviews…