CVE-2026-7831
Açıklama (NVD)
UltraVNC viewer through 1.8.2.2 contains an off-by-one stack buffer overflow in the RFB ServerInit message handler. In vncviewer/ClientConnection.cpp, when the server-supplied nameLength equals exactly 2024 the code declares a 2024-byte stack buffer _dn[2024] and calls ReadString(_dn, 2024). ReadString writes the NUL terminator at buf[length], i.e., _dn[2024], one byte past the end of the stack buffer. A malicious VNC server can trigger this condition by advertising a desktop name of length 2024 in its ServerInit message. On release builds without stack canaries the single-byte NUL overwrite adjacent stack data. On builds with /GS stack protection the canary is corrupted and the process terminates, resulting in denial of service. User interaction (connecting the viewer to the malicious server) is required.
Yayın: 01.07.2026 · Son değişiklik: 25.10.2026 · Zayıflık: CWE-193, CWE-787
CVSS 3.1 metrikleri
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
| Saldırı vektörü | Ağ (uzaktan) |
| Karmaşıklık | Düşük |
| Gereken yetki | Yok |
| Kullanıcı etkileşimi | Gerekli |
| Kapsam | Değişmez |
| Gizlilik | Düşük |
| Bütünlük | Düşük |
| Erişilebilirlik | Yüksek |
Hesaplanan temel puan: 7.6. CVSS hesaplayıcıda incele