9.8 Critical

CVE-2026-117862 Privilege escalation due to incorrect boundary conditions in the Networking component

Description

Privilege escalation due to incorrect boundary conditions in the Networking component. This vulnerability was fixed in Firefox 159, Firefox ESR 115.44, Firefox ESR 153.6, Thunderbird 159, and Thunderbird 153.6.

CVSS 3.1 detail

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

Exploitable remotely over the network, without an account and without any user action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector: Network
Attack complexity: Low
Privileges required: None
Interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Affected products and versions

Product	Affected versions	Fixed in
Firefox 159	earliest → < 159	159
Firefox 153.6	earliest → < 153.6	153.6
Firefox 115.44	earliest → < 115.44	115.44
Thunderbird 159	earliest → < 159	159
Thunderbird 153.6	earliest → < 153.6	153.6

References

bugzilla.mozilla.org bugzilla.mozilla.org
www.mozilla.org www.mozilla.org
www.mozilla.org www.mozilla.org
www.mozilla.org www.mozilla.org
www.mozilla.org www.mozilla.org
www.mozilla.org www.mozilla.org

Timeline

Published October 27, 2026
Last modified November 4, 2026

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