Medium 6.5Published Mar 24, 2026

CVE-2026-3889Spoofing issue in Thunderbird.

Updated under an hour ago (2026-10-19 06:10 UTC)

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It affects mozilla thunderbird. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

Spoofing issue in Thunderbird. This vulnerability was fixed in Thunderbird 149 and Thunderbird 140.9.

CVSS: 6.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-451
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Modified
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

mozilla thunderbird mozilla:thunderbird	before 140.9.0; before 149.0	NVD

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2020723permissions-required
https://www.mozilla.org/security/advisories/mfsa2026-23/vendor-advisory
https://www.mozilla.org/security/advisories/mfsa2026-24/vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.