Medium (5.9) in mozilla network security services. EPSS 1.5% chance of exploitation in the next 30 days.
When handling a SSLv2-compatible ClientHello request, the server doesn't generate a new random value but sends an all-zero value instead. This results in full malleability of the ClientHello for SSLv2 used for TLS 1.2 in all versions prior to NSS 3.39. This does not impact TLS 1.3.
Severity
CVSS 3.0
5.9 medium
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
1.5% chance of exploitation in the next 30 days; higher than 73% of CVEs (scores of 2026-10-31)