Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
AV AC PR UI S C I A CVSS EPSS %ile KEV N L N N U L N N 5.3 .0024 14.5 —
AFFECTED Product Versions Fixed Zephyr unspecified —
TIMELINE Jan 30 Reserved by zephyr May 11 Published (CNA: zephyr) Oct 15 EXPLOIT PUBLISHED — CVE-2026-1677 (zephyrproject-rtos Zephyr). Public exploit reference added.
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.
| Date | Event | Detail |
|---|---|---|
| January 30, 2026 | Reserved | Reserved by zephyr |
| May 11, 2026 | Published | Published (CNA: zephyr) |
| October 15, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-1677 (zephyrproject-rtos Zephyr). Public exploit reference added. |
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|---|---|---|---|
| zephyrproject-rtos | Zephyr | — | — | — |
Authoritative record: CVE-2026-1677 at cve.org
Vendors: zephyrproject-rtos
Weaknesses: CWE-757
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-1677 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
