PT-2026-118618 · Mozilla · Thunderbird

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CVE-2026-113866

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Published

2026-10-20

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Updated

2026-10-20

CVSS v3.1

5.9

Medium

VectorAV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
When setting up an account, Thunderbird's Exchange AutoDiscover lookup also queried the domain's AutoDiscover service over plain HTTP. Due to a bug, that unencrypted request included the credentials the user had entered, allowing a network attacker to obtain the user's password. This vulnerability was fixed in Thunderbird 158.0.1 and Thunderbird 153.5.1.

Fix

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Weakness Enumeration

Related Identifiers

CVE-2026-113866

Affected Products

Thunderbird