Use-after-free in PQC hybrid key-share handling. This is an incomplete-fix follow-up to CVE-2026-5460 (released in 5.9.1): a malicious TLS 1.3 server sending a truncated PQC hybrid KeyShare can still trigger the error cleanup path to operate on freed memory.
Exploitability
AV:NAC:HAT:PPR:NUI:PVulnerable System
VC:NVI:NVA:LSubsequent System
SC:NSI:NSA:N2.3/CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NMemory Safety