CVE-2026-100764: Mozilla Thunderbird · Memory Buffer Overflow
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
Users should update Mozilla Thunderbird to version 157 or later, where this vulnerability has been fixed. No other mitigation is required as the vendor has provided an official fix.
Description
CVE-2026-100764 is a high-severity privilege escalation vulnerability in Mozilla Thunderbird caused by incorrect boundary conditions in the Graphics: WebGPU component. The flaw allows an attacker to escalate privileges. This vulnerability was fixed in Thunderbird version 157.