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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 140.6 as a priority.

Data as of 26 Oct 2026, 14:05 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 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 140.6.

Affected software

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

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 for Red Hat Enterprise Linux 8.4 variants that address these vulnerabilities. Users should apply the official security update RHSA-2026:0023 to upgrade to Thunderbird ESR 140.6 or later. For detailed update instructions, refer to the Red Hat advisory and article at https://access.redhat.com/articles/11258. No additional mitigation steps are specified or required beyond applying the official patch.

Description

Multiple security vulnerabilities affecting Mozilla Thunderbird have been addressed in a Red Hat security advisory. These include memory safety bugs, use-after-free, JIT miscompilation, sandbox escape, privilege escalation, and same-origin policy bypass issues. The vulnerabilities affect Thunderbird ESR 140.0 up to but not including 140.6 on Red Hat Enterprise Linux 8.4 variants. Red Hat has released updated packages to remediate these issues.

References

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