CVE-2026-12304

9.1 CRITICAL

Published: June 16, 2026 Modified: June 16, 2026

Description

Same-origin policy bypass in the Networking: Cookies component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Thunderbird 152, and Thunderbird 140.12.

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

CVSS v3.x Details

0.0 Low Medium High Critical 10.0

Vector String

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

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory

https://bugzilla.mozilla.org/show_bug.cgi?id=2034944

Source: security@mozilla.org

https://www.mozilla.org/security/advisories/mfsa2026-57/

Source: security@mozilla.org

https://www.mozilla.org/security/advisories/mfsa2026-58/

Source: security@mozilla.org

https://www.mozilla.org/security/advisories/mfsa2026-60/

Source: security@mozilla.org

https://www.mozilla.org/security/advisories/mfsa2026-61/

Source: security@mozilla.org

5 reference(s) from NVD

Quick Stats

CVSS v3 Score

9.1 / 10.0

EPSS (Exploit Probability)

0.2%

9th percentile

Exploitation Status

Not in CISA KEV

Weaknesses (CWE)

CWE-346

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