CVE-2026-92238: Mozilla Thunderbird · CWE-444
Affects Mozilla ThunderbirdSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical · fixed in 140.16 : patch Mozilla Thunderbird as a priority.
Data as of 30 Oct 2026, 20:25 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 45% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 140.16
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 15 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Thunderbird | Affected
| Fixed in
|
AI-suggested
This vulnerability has been fixed in Thunderbird versions 140.16 and 156. Users should update to at least Thunderbird 140.16 or later to mitigate this issue. Since this is not a cloud service, manual patching is required. No additional mitigation actions are specified by the vendor, and the advisory notes that exploitation through email is generally not feasible.
Description
A maliciously constructed mail header could lead to multiple fields being parsed as one, or potential memory safety violations. This vulnerability was fixed in Thunderbird 156, Thunderbird 140.16, and Thunderbird 153.3.