CVE-2026-84639 Affecting thunderbird package, versions <1:140.15.0esr-1~deb12u1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN12-THUNDERBIRD-19500609
- published2 Sept 2026
- disclosed1 Sept 2026
Introduced: 1 Sep 2026
NewCVE-2026-84639 (opens in a new tab)How to fix?
Upgrade Debian:12 thunderbird to version 1:140.15.0esr-1~deb12u1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream thunderbird package and not the thunderbird package as distributed by Debian.
See How to fix? for Debian:12 relevant fixed versions and status.
Triggering an error condition in certain MIME bodies would cause uninitialized memory to be used. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.