« Back to list

CVE-2026-107614

Status: Awaiting AnalysisMedium (6.1)—

An integer underflow in WinCursorShapeUtils::trimTransparent() in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to crash the server, and potentially read out-of-bounds memory, by causing a cursor shape with a width or height of zero to be processed on the DXGI capture path. The loop bound width - 1 wraps to 0xFFFFFFFF, producing an access roughly 4 GB beyond the 64 KB cursor buffer; a monochrome cursor of height 1 also becomes 0 because getCursorHeight() halves the height in place.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

🎯 ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

AV:L + PR:L sin UI permite escalada local. Integer underflow causa lectura OOB (out-of-bounds memory) y crash del servidor (DoS).

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

🛡️ ATT&CK mitigations that cover these techniques

Threat Intelligence ProgramFilter Network TrafficExecution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate Software

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Glavsoft — Tightvnc ServerAI

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-107614",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-107614",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-08T14:00:49.369592Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.1,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "LOW"
        },
        "impactScore": 4.2,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "affected": [
    {
      "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c",
      "affectedData": [
        {
          "vendor": "GlavSoft",
          "modules": [
            "TightVNC Server (cursor shape processing)"
          ],
          "product": "TightVNC",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "2.8.88",
              "versionType": "custom"
            }
          ],
          "platforms": [
            "Windows"
          ],
          "programFiles": [
            "WinCursorShapeUtils.cpp"
          ],
          "defaultStatus": "unaffected",
          "programRoutines": [
            {
              "name": "WinCursorShapeUtils::trimTransparent()"
            },
            {
              "name": "getCursorHeight()"
            }
          ]
        }
      ]
    }
  ],
  "published": "2026-10-08T14:16:50.163",
  "references": [
    {
      "url": "https://sourceforge.net/p/vnc-tight/bugs/1661/",
      "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c"
    },
    {
      "url": "https://www.tightvnc.com/whatsnew.php",
      "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c"
    }
  ],
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "33c584b5-0579-4c06-b2a0-8d8329fcab9c",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        },
        {
          "lang": "en",
          "value": "CWE-191"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "An integer underflow in WinCursorShapeUtils::trimTransparent() in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to crash the server, and potentially read out-of-bounds memory, by causing a cursor shape with a width or height of zero to be processed on the DXGI capture path. The loop bound width - 1 wraps to 0xFFFFFFFF, producing an access roughly 4 GB beyond the 64 KB cursor buffer; a monochrome cursor of height 1 also becomes 0 because getCursorHeight() halves the height in place."
    }
  ],
  "lastModified": "2026-10-08T21:10:00.133",
  "sourceIdentifier": "33c584b5-0579-4c06-b2a0-8d8329fcab9c"
}