{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-103010",
        "assignerOrgId": "ceab7361-8a18-47b1-92ba-4d7d25f6715a",
        "state": "PUBLISHED",
        "assignerShortName": "GitLab",
        "dateReserved": "2026-09-29T21:04:45.349Z",
        "datePublished": "2026-10-08T10:53:10.627Z",
        "dateUpdated": "2026-10-08T10:53:10.627Z"
    },
    "containers": {
        "cna": {
            "title": "Heap-based Buffer Overflow in hMailServer",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Heap-based buffer overflow in the legacy Blowfish decryption routine (BlowFishEncryptor::DecryptFromString) in Progressive Robot hMailServer 6.0.0 through 6.3.3 on Windows allows a local interactive user with no hMailServer credentials to write bytes of their choosing past the end of a 255-byte heap buffer in the hMailServer service process, which runs as LocalSystem by default. The user does this by passing a long hexadecimal string to the COM method Utilities.BlowfishDecrypt, which checked no authentication. The routine converted hexadecimal input of any length into a fixed 255-byte buffer before decrypting it in place. The result is a denial of service (service crash), and possibly code execution with the privileges of the service account."
                }
            ],
            "affected": [
                {
                    "vendor": "Progressive Robot Ltd",
                    "product": "hMailServer",
                    "repo": "https://gitlab.com/hmailserver/hmailserver",
                    "versions": [
                        {
                            "version": "6.0.0",
                            "status": "affected",
                            "lessThan": "6.3.4",
                            "versionType": "semver"
                        }
                    ],
                    "defaultStatus": "unaffected"
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "CWE-122: Heap-based Buffer Overflow",
                            "cweId": "CWE-122",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://gitlab.com/hmailserver/hmailserver/-/commit/135a1908ff820ed587d5f180f98c53bd010d8931"
                },
                {
                    "url": "https://gitlab.com/hmailserver/hmailserver/-/releases/v6.3.4"
                },
                {
                    "url": "https://gitlab.com/hmailserver/hmailserver/-/work_items/49"
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                        "attackVector": "LOCAL",
                        "attackComplexity": "LOW",
                        "privilegesRequired": "LOW",
                        "userInteraction": "NONE",
                        "scope": "UNCHANGED",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "availabilityImpact": "HIGH",
                        "baseScore": 7.8,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "Upgrade to hMailServer 6.3.6, which also requires authentication for the COM Utilities helpers (6.3.4 is the first release with this routine fixed)."
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "value": "Found in the hMailServer project's own code review (Progressive Robot Ltd)",
                    "type": "finder"
                }
            ],
            "providerMetadata": {
                "orgId": "ceab7361-8a18-47b1-92ba-4d7d25f6715a",
                "shortName": "GitLab",
                "dateUpdated": "2026-10-08T10:53:10.627Z"
            }
        }
    }
}