Vulnerability details

CVE-2026-16381

Same-origin policy bypass in the Networking: DNS component

CVSS 3.1

9.1Critical

Official 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.

CVSS scores

Score	Version	Source	Vector
9.1Critical	3.1	CISA ADP / Vulnrichment (CISA-ADP)	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`

Affected products

Vendor	Product	Versions	Source
No product information recorded.

References and advisories

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Details

Published: 2026-07-21
Last updated: 2026-07-22
State: Published
Assigner (CNA): mozilla

Exploit prediction (EPSS)

0.17%

Probability of exploitation in 30 days

6.8%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: Yes
Exploitation: None
Technical impact: Total

Weaknesses (CWE)

CWE-346
Origin Validation Error