Signal is active with 2 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD description
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.
Priority
LOW
Exploitation
NONE
PoC
YES
Patch
AVAILABLE
Momentum
NONE
If you run products in this scope, you should treat this CVE as relevant to your environment.
CVE-2026-1677 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 … https://www.cve.org/CVERecord?id=CVE-2026-1677
Post summary
The post discloses that Zephyr sockets may downgrade from TLS 1.3 to TLS 1.2 when both versions are enabled, revealing a protocol downgrade flaw.
CVE-2026-1677 TLS Version Negotiation Bypass in Zephyr Sockets with IPPROTO_TLS_1_3 https://vulmon.com/vulnerabilitydetails?qid=CVE-2026-1677
Post summary
The entry references CVE-2026-1677, describing it as a TLS version negotiation bypass in Zephyr sockets, but provides neither exploit proof, remediation advice nor evidence of active exploitation.
1 of 1 entries
| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| OS | zephyrproject | zephyr | - | - | - |