CVE-2026-16388 — CRITICAL (9.8)

Q: What is CVE-2026-16388?

CVE-2026-16388 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

Q: How severe is CVE-2026-16388?

CVE-2026-16388 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Q: Is there a patch for CVE-2026-16388?

Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.

Vulnerability Description

Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

CVSS Score

9.8

CRITICAL

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Affected Products

Vendor	Product	Versions
Mozilla	Firefox	< 153.0.0
Mozilla	Thunderbird	< 153.0

Related Weaknesses (CWE)

CWE-693

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2043845Permissions Required
https://www.mozilla.org/security/advisories/mfsa2026-68/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2026-71/Vendor Advisory

FAQ

What is CVE-2026-16388?

CVE-2026-16388 is a vulnerability with a CVSS score of 9.8 (CRITICAL). Sandbox escape in the DOM: Networking component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.

How severe is CVE-2026-16388?

CVE-2026-16388 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2026-16388?

Check the references section above for vendor advisories and patch information. Affected products include: Mozilla Firefox, Mozilla Thunderbird.