CVE-2026-100813: Mozilla Thunderbird · CWE-763
Affects Mozilla ThunderbirdSource CVE Database V5
Not known to be exploited · CVSS 8.8 High.
Data as of 12 Nov 2026, 23:24 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 14% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 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 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Thunderbird | Affected
| Fixed in
|
AI-suggested
A fix is available in Thunderbird version 157. Users and administrators should update to version 157 or later to remediate this vulnerability. Refer to the official Mozilla security advisory at https://www.mozilla.org/security/advisories/mfsa2026-97/ for detailed guidance.
Description
CVE-2026-100813 is a high-severity vulnerability in Mozilla Thunderbird involving an invalid pointer in the JavaScript Engine's JIT component. This flaw allows potential high impact on confidentiality, integrity, and availability. The issue was fixed in Thunderbird version 157.