Red Hat Security Advisory: thunderbird security update
Affects Red Hat thunderbirdSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.8 Critical : upgrade Red Hat thunderbird to 140.4 as a priority.
Data as of 26 Oct 2026, 11:07 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 140.4
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 14 Oct 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade Red Hat thunderbird to 140.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Red Hat Product Security Red Hat | Affected
| Fixed in
|
AI-suggested
A security update for Thunderbird is available for Red Hat Enterprise Linux 9.4 Extended Update Support, which includes fixes for all listed vulnerabilities. Users should apply the Thunderbird update to version 140.4 or later as provided by Red Hat. For detailed update instructions, refer to the Red Hat advisory at https://access.redhat.com/articles/11258. No additional mitigations are specified beyond applying the official update.
Description
Multiple security vulnerabilities affecting Mozilla Thunderbird have been addressed in a Red Hat security update for Red Hat Enterprise Linux 9.4 Extended Update Support. The issues include memory safety bugs, out-of-bounds read/write, use-after-free, cross-process information leaks, and improper handling of object properties and content types. These vulnerabilities are fixed in Thunderbird ESR 140.4 and Thunderbird 144 versions. The update is rated as important by Red Hat Product Security.
References
- access.redhat.com/errata/RHSA-2025:19945 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403763 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403765 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403768 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403769 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403770 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403774 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2403776 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2025/rhsa-2025_19945.json (opens in a new tab)