Answer in brief
CVE-2026-1677 records a Medium severity (CVSS 5.3) vulnerability in net: TLS 1.2 connections allowed on TLS 1.3 sockets. The current sources do not mark it as known exploited. The current feed maps zephyrproject-rtos/Zephyr (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps zephyrproject-rtos/Zephyr (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| zephyrproject-rtos/Zephyrgeneric | * | Not reported |
Published upstream
May 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 8, 2026
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.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-1677 records a Medium severity (CVSS 5.3) vulnerability in net: TLS 1.2 connections allowed on TLS 1.3 sockets. The current sources do not mark it as known exploited. The current feed maps zephyrproject-rtos/Zephyr (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps zephyrproject-rtos/Zephyr (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| zephyrproject-rtos/Zephyrgeneric | * | Not reported |
Published upstream
May 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 8, 2026
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.
Quoted source text, attributed separately from HOL analysis.