CVE-2016-8635: Mozilla Network Security Services

Medium severity, CVSS 5.9. EPSS: 2% chance of exploitation in the next 30 days.

It was found that Diffie Hellman Client key exchange handling in NSS 3.21.x was vulnerable to small subgroup confinement attack. An attacker could use this flaw to recover private keys by confining the client DH key to small subgroup of the desired group.

Affected products

• Mozilla Network Security Services: from 3.21, up to and including 3.21.4
• Red Hat Enterprise Linux Desktop: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server: version 5.0 only; version 6.0 only; version 7.0 only
• Red Hat Enterprise Linux Server Aus: version 7.3 only; version 7.4 only; version 7.6 only
• Red Hat Enterprise Linux Server Eus: version 7.3 only; version 7.4 only; version 7.5 only; version 7.6 only
• Red Hat Enterprise Linux Server Tus: version 7.3 only; version 7.6 only
• Red Hat Enterprise Linux Workstation: version 5.0 only; version 6.0 only; version 7.0 only

Published 2018-08-01. Last modified 2026-06-17.