Vulnerability · NVD

CVE-2026-118176

CVE-2026-118176, Severity pending severity (CVSS —): 1 tracked app concerned, all fixed or indeterminable on their current version.

Severity (CVSS): -
Exploitation: -
Tracked apps: 1
Still exposed: 0

Published on 2026-10-27

Thunderbird's check that prevents mailbox: URLs from accessing files on remote Windows network shares could be bypassed using extended-length UNC paths. Displaying a specially crafted email could cause Thunderbird to connect to an SMB server chosen by the attacker, disclosing the user's Windows account name and NTLM authentication data, which could be used for offline password cracking or relay attacks.
This bug only affects Thunderbird on Windows. Other operating systems are unaffected. This vulnerability was fixed in Thunderbird 159 and Thunderbird 153.6.

Tracked apps referencing this CVE

For each app: the affected range, the fixing version, and where the tracked app stands today.

Mozilla Thunderbird Windows winget:Mozilla.Thunderbird

Affected <159 Fixed in 159 Latest tracked 159.0 patched

Observed affected builds (137)

158.0.1 158.0 157.0.1 157.0 156.0.1 156.0 155.0.1 155.0 154.0 153.0.3 153.0.2 153.0.1 153.0 152.0.1 152.0 151.0.1 151.0 150.0.2 150.0.1 150.0 149.0.2 149.0.1 149.0 148.0.1 148.0 147.0.2 147.0.1 147.0 146.0.1 146.0 +107 · see history

Vulnerable CPE configurations (1)

Vendor	Product	Platform	Versions	CPE 2.3 URI
mozilla	thunderbird All platforms (wildcard)	All platforms (wildcard)	<159	cpe:2.3:a:mozilla:thunderbird::::::::

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