High (7.5) in golang go. EPSS 0.6% chance of exploitation in the next 30 days. Fixed in stdlib 1.25.9, 1.26.2.
If one side of the TLS connection sends multiple key update messages post-handshake in a single record, the connection can deadlock, causing uncontrolled consumption of resources. This can lead to a denial of service. This only affects TLS 1.3.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.6% chance of exploitation in the next 30 days; higher than 49% of CVEs (scores of 2026-10-31)