Red Hat Security Advisory: thunderbird security update
Affects Red Hat thunderbirdSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 9.8 Critical · fixed in Red Hat package updates : patch Red Hat thunderbird as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- 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:HExploitation evidence
Disclosed: evidence found.
CVE published 9 Dec 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
AI-suggested
Red Hat has released updated Thunderbird packages (ESR 140.6 and 146) that address these vulnerabilities. Users of Red Hat Enterprise Linux 8.6 and related update services should apply the Thunderbird updates as described in the Red Hat advisory (https://access.redhat.com/articles/11258) to remediate these issues. Since this is a traditional software package, patching the affected Thunderbird versions is the recommended mitigation. No vendor advisory states that no action is required or that the issues are already mitigated without updates.
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 fixes are included in Thunderbird ESR 140.6 and Thunderbird 146 updates. The advisory covers Red Hat Enterprise Linux 8.6 variants and related update services. Red Hat Product Security rates these vulnerabilities as having high severity.
References
- access.redhat.com/errata/RHSA-2026:0022 (opens in a new tab)
- access.redhat.com/security/updates/classification/ (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420502 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420503 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420504 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420506 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420508 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420509 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420512 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420513 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420516 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2420517 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_0022.json (opens in a new tab)