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CVE-2026-1677

net: TLS 1.2 connections allowed on TLS 1.3 sockets PUBLISHED

Description (CNA)

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 peer can establish TLS 1.2, so applications that assumed `IPPROTO_TLS_1_3` enforces TLS 1.3 may silently use TLS 1.2 and remain exposed to TLS 1.2-specific weaknesses. As a workaround, the `TLS_CIPHERSUITE_LIST` socket option can be restricted to TLS 1.3-only cipher suites.

Affected (CNA)

Vendor / productVersions
zephyrproject-rtos / Zephyraffected * before 4.4.0

CWE

CWE-757

References

ADP enrichment

CISA-ADP

No English description supplied.