cvedb.io
CVE-2026-1677
MEDIUM · CVSS 5.3
EPSS exploitation probability: 0%
Published 2026-05-11T06:16:08.683 · Last modified 2026-06-17T10:16:18.050

Summary

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.

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.