CVE-2026-113866

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 62/100
Published: 2026-10-20 Modified: 2026-10-22 First seen: 2026-10-29 Status: active

Attack Surface

Network No Auth No Interaction Conf. Impact

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: Unchanged
C: High
I: None
A: None

Description

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.

Weakness Classification (1)

Bug Bounty Relevance

62 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

5.9 / 10.0 v3.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

EPSS — Exploitation Probability

0.36%
Raw Score 0.003650
Percentile 30.3%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00365
2026-10-28
0.00365

Intelligence Sources

nvd ref →