{
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    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-1677",
        "assignerOrgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
        "state": "PUBLISHED",
        "assignerShortName": "zephyr",
        "dateReserved": "2026-01-30T05:38:22.811Z",
        "datePublished": "2026-05-11T05:52:12.140Z",
        "dateUpdated": "2026-10-15T22:10:21.970Z"
    },
    "containers": {
        "cna": {
            "affected": [
                {
                    "defaultStatus": "unaffected",
                    "packageName": "Zephyr",
                    "product": "Zephyr",
                    "repo": "https://github.com/zephyrproject-rtos/zephyr",
                    "vendor": "zephyrproject-rtos",
                    "versions": [
                        {
                            "lessThan": "4.4.0",
                            "status": "affected",
                            "version": "*",
                            "versionType": "git"
                        }
                    ]
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
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                            "base64": false,
                            "type": "text/html",
                            "value": "net:  TLS 1.2 connections allowed  on TLS 1.3 sockets"
                        }
                    ],
                    "value": "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."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.3,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "LOW",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
                        "version": "3.1"
                    },
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ]
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-757",
                            "description": "Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-23r2-m5wx-4rvq"
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "net:  TLS 1.2 connections allowed  on TLS 1.3 sockets",
            "x_generator": {
                "engine": "swg-tools/create-cve-info"
            },
            "providerMetadata": {
                "orgId": "e2e69745-5e70-4e92-8431-deb5529a81ad",
                "shortName": "zephyr",
                "dateUpdated": "2026-10-15T22:10:21.970Z"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-23r2-m5wx-4rvq",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-05-11T16:31:12.694213Z",
                                "id": "CVE-2026-1677",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-05-11T16:31:22.202Z"
                }
            }
        ]
    }
}