CVE-2026-84641

Publication date 1 September 2026

Last updated 16 September 2026


Ubuntu priority

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

A malicious IMAP server can trigger use-after-free and heap-memory disclosure by sending a crafted ID response. Heap contents can ultimately be persisted to prefs.js. This vulnerability was fixed in Thunderbird 155, Thunderbird 140.15, and Thunderbird 153.2.

Status

Package Ubuntu Release Status
thunderbird 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N


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