{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-128321",
        "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b",
        "state": "PUBLISHED",
        "assignerShortName": "certcc",
        "dateReserved": "2026-11-13T00:02:00.631Z",
        "datePublished": "2026-11-13T00:08:32.021Z",
        "dateUpdated": "2026-11-13T02:05:51.969Z"
    },
    "containers": {
        "cna": {
            "title": "Tight JPEG decoding in TightVNC and UltraVNC viewers contains a heap-based buffer overflow vulnerability",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Tight JPEG decoding in TightVNC and UltraVNC viewers contains a heap-based buffer overflow because an attacker-controlled framebuffer rectangle width is not validated against a fixed-size decoding buffer. A malicious VNC server can cause an out-of-bounds heap write when a user connects, resulting in application crash and potentially other memory-corruption impacts."
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "affected": [
                {
                    "vendor": "UltraVNC",
                    "product": "UltraVNC",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "1.8.2.4",
                            "lessThanOrEqual": "1.8.2.6",
                            "versionType": "custom"
                        }
                    ]
                },
                {
                    "vendor": "Glavsoft (TightVNC)",
                    "product": "TightVNC",
                    "versions": [
                        {
                            "status": "affected",
                            "version": "1.3.10",
                            "lessThanOrEqual": "1.3.10",
                            "versionType": "custom"
                        }
                    ]
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "description": "CWE-122 Heap-Based Buffer Overflow"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://www.tightvnc.com/"
                },
                {
                    "url": "https://github.com/ultravnc/ultravnc"
                }
            ],
            "x_generator": {
                "engine": "VINCE 4.0.3",
                "env": "prod",
                "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-128321"
            },
            "providerMetadata": {
                "orgId": "37e5125f-f79b-445b-8fad-9564f167944b",
                "shortName": "certcc",
                "dateUpdated": "2026-11-13T00:08:32.021Z"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "https://www.kb.cert.org/vuls/id/644655"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2026-11-13T02:05:51.969Z"
                }
            }
        ]
    }
}