Vulnerability · NVD

CVE-2026-16405

CVE-2026-16405, high severity (CVSS 7.5): 1 tracked app concerned, all fixed or indeterminable on their current version.

Severity (CVSS): 7.5
Exploitation: 0.3 %
Tracked apps: 1
Still exposed: 0

Published on 2026-07-21

Information disclosure in the Networking: WebSockets component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.

Attack vector : Network No privileges required No user interaction

Show raw CVSS vector

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

EPSS 0.26% exploit very unlikely percentile 17.0%

Tracked apps referencing this CVE

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

Mozilla Firefox Windows winget:Mozilla.Firefox

Affected ≥140.1.0 <140.13.0 Fixed in 140.13.0 Latest tracked 154.0.1 patched

Vulnerable CPE configurations (2)

Vendor	Product	Platform	Versions	CPE 2.3 URI
mozilla	firefox All platforms (wildcard)	All platforms (wildcard)	<153.0.0	cpe:2.3:a:mozilla:firefox:::::-:::*
mozilla	firefox All platforms (wildcard)	All platforms (wildcard)	≥140.1.0 <140.13.0	cpe:2.3:a:mozilla:firefox:::::esr:::*

View on NVD ↗ Advisory · www.mozilla.org