CVE-2026-15924 Use-after-free / double-free from unsynchronized concurrent access to the TLS client session cache in Zephyr sockets

Zephyr's TLS socket layer in subsys/net/lib/sockets/socketstls.c keeps a single process-global array, clientcache, of cached client sessions that is shared by every TLS socket context. The functions that mutate and read it — tlssessionsave, tlssessionget, tlssessioncachereset, and the settings...

CVE-2026-1677

Zephyr sockets created with IPPROTOTLS13 can still negotiate a TLS 1.2 connection when both TLS versions are enabled in Kconfig, because the socket-level protocol selection is not propagated to mbedTLS e.g. via mbedtlssslconfmintlsversion. The ClientHello advertises both versions and the peer can...

CVE-2026-1677

Zephyr sockets created with IPPROTOTLS13 can still negotiate a TLS 1.2 connection when both TLS versions are enabled in Kconfig, because the socket-level protocol selection is not propagated to mbedTLS e.g. via mbedtlssslconfmintlsversion. The ClientHello advertises both versions and the peer can...

CVE-2026-1677

Zephyr sockets created with IPPROTOTLS13 can still negotiate a TLS 1.2 connection when both TLS versions are enabled in Kconfig, because the socket-level protocol selection is not propagated to mbedTLS e.g. via mbedtlssslconfmintlsversion. The ClientHello advertises both versions and the peer can...

CVE-2026-1677 net: TLS 1.2 connections allowed on TLS 1.3 sockets

Zephyr sockets created with IPPROTOTLS13 can still negotiate a TLS 1.2 connection when both TLS versions are enabled in Kconfig, because the socket-level protocol selection is not propagated to mbedTLS e.g. via mbedtlssslconfmintlsversion. The ClientHello advertises both versions and the peer can...

CVE-2026-1677

CVE-2026-1677 concerns Zephyr: sockets created with IPPROTO_TLS_1_3 may still negotiate TLS 1.2 when both TLS versions are enabled, because socket‑level protocol selection isn’t propagated to mbedTLS (e.g., via mbedtls_ssl_conf_min_tls_version). The ClientHello can advertise both TLS 1.2 and TLS ...

PT-2026-39574

Zephyr sockets created with IPPROTO TLS 1 3 can still negotiate a TLS 1.2 connection when both TLS versions are enabled in Kconfig, because the socket-level protocol selection is not propagated to mbedTLS e.g. via mbedtls ssl conf min tls version. The ClientHello advertises both versions and the...