CVE-2026-16381

Published Jul 21, 2026

Last updated 7 hours ago

CVSS critical 9.1
Firefox
Firefox ESR

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-16381 is a vulnerability identified in Mozilla Firefox, categorized as a same-origin policy bypass within the browser's Networking: DNS component. This flaw involves the manipulation of an unspecified part of the DNS component, leading to a cross-domain policy vulnerability. The issue is known to affect confidentiality. The vulnerability was addressed in Firefox version 153 and Firefox ESR 140.13. Exploitation of CVE-2026-16381 can be carried out remotely and requires some form of user interaction.

Description
Same-origin policy bypass in the Networking: DNS component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
Source
security@mozilla.org
NVD status
Undergoing Analysis

Risk scores

CVSS 3.1

Type
Secondary
Base score
9.1
Impact score
5.2
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Severity
CRITICAL

Weaknesses

134c704f-9b21-4f2e-91b3-4a467353bcc0
CWE-346

Social media

Hype score is a measure of social media activity compared against trending CVEs from the past 12 months. Max score 100.

Hype score

16