{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-107611",
        "assignerOrgId": "33c584b5-0579-4c06-b2a0-8d8329fcab9c",
        "state": "PUBLISHED",
        "assignerShortName": "securin",
        "dateReserved": "2026-10-08T13:23:07.677Z",
        "datePublished": "2026-10-08T13:39:48.883Z",
        "dateUpdated": "2026-10-08T14:03:01.404Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "33c584b5-0579-4c06-b2a0-8d8329fcab9c",
                "shortName": "securin",
                "dateUpdated": "2026-10-08T13:39:48.883Z"
            },
            "title": "Out-of-bounds read in TightVNC Viewer ZRLE palette decoding",
            "descriptions": [
                {
                    "lang": "en",
                    "value": "An out-of-bounds read vulnerability in the ZRLE decoder of GlavSoft TightVNC Viewer for Windows before 2.8.88 allows a malicious or compromised VNC server to read heap memory beyond the palette allocation and crash the viewer by sending ZRLE-encoded tiles whose palette indices exceed the declared palette size. readPaletteRleTile() and readPackedPaletteTile() use the attacker-supplied index to look up colours without validating it against the palette size; out-of-bounds heap data is copied into the framebuffer (garbled display) or the read faults, terminating the viewer."
                }
            ],
            "affected": [
                {
                    "vendor": "GlavSoft",
                    "product": "TightVNC",
                    "platforms": [
                        "Windows"
                    ],
                    "modules": [
                        "TightVNC Viewer (ZRLE decoder)"
                    ],
                    "programFiles": [
                        "ZrleDecoder.cpp"
                    ],
                    "programRoutines": [
                        {
                            "name": "readPaletteRleTile()"
                        },
                        {
                            "name": "readPackedPaletteTile()"
                        }
                    ],
                    "defaultStatus": "unaffected",
                    "versions": [
                        {
                            "version": "0",
                            "lessThan": "2.8.88",
                            "status": "affected",
                            "versionType": "custom"
                        }
                    ]
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "type": "CWE",
                            "cweId": "CWE-125",
                            "description": "CWE-125 Out-of-bounds Read"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ],
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H",
                        "baseScore": 7.1,
                        "baseSeverity": "HIGH"
                    }
                }
            ],
            "solutions": [
                {
                    "lang": "en",
                    "value": "Upgrade TightVNC for Windows to version 2.8.88 or later."
                }
            ],
            "references": [
                {
                    "url": "https://sourceforge.net/p/vnc-tight/bugs/1657/",
                    "name": "TightVNC bug #1657",
                    "tags": [
                        "issue-tracking"
                    ]
                },
                {
                    "url": "https://www.tightvnc.com/whatsnew.php",
                    "name": "TightVNC release notes (2.8.88)",
                    "tags": [
                        "release-notes",
                        "patch"
                    ]
                }
            ],
            "credits": [
                {
                    "lang": "en",
                    "type": "finder",
                    "value": "Arjun Basnet from Securin"
                }
            ],
            "timeline": [
                {
                    "time": "2026-05-30T00:00:00.000Z",
                    "lang": "en",
                    "value": "Reported to GlavSoft"
                },
                {
                    "time": "2026-06-02T00:00:00.000Z",
                    "lang": "en",
                    "value": "Vendor acknowledged"
                },
                {
                    "time": "2026-06-19T00:00:00.000Z",
                    "lang": "en",
                    "value": "TightVNC 2.8.88 released with fix"
                }
            ],
            "source": {
                "discovery": "EXTERNAL"
            },
            "impacts": [
                {
                    "capecId": "CAPEC-540",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-540 Overread Buffers"
                        }
                    ]
                }
            ],
            "workarounds": [
                {
                    "lang": "en",
                    "value": "Connect only to trusted VNC servers until the viewer is upgraded."
                }
            ]
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-10-08T14:02:42.563819Z",
                                "id": "CVE-2026-107611",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "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": "2026-10-08T14:03:01.404Z"
                }
            }
        ]
    }
}