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CVE-2026-7840

CRITICAL · CVSS 9.8 Public Exploit

Kaynak: NVD + CISA KEV + EPSS · Yayınlanma: 2026-07-01T05:16:24.820 · Çekilme zamanı: 2026-07-01T06:12:22.721766+00:00

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Uzaktan istismar edilebilir olabilir.

Public Exploit Sinyali

Bu CVE için açıklama veya referanslarda public exploit / PoC / GitHub / Metasploit sinyali tespit edildi.

Tespit Edilen Sinyaller
arbitrary code execution code execution
GitHub PoC Linkleri

Not: Bu bağlantılar yalnızca güvenlik araştırması ve doğrulama amacıyla listelenmiştir.

CVE
CVE-2026-7840
Severity
CRITICAL
CVSS
9.8
EPSS
Yok

Orijinal NVD Açıklaması

UltraVNC repeater through 1.8.2.2 contains a global buffer overflow in its embedded HTTP administration server. The functions wi_senderr() and wi_replyhdr() in repeater/webgui/webutils.c write the caller-supplied HTTP request URI into a fixed 1000-byte global buffer (hdrbuf) via unchecked sprintf calls. The HTTP receive buffer accepts URIs up to approximately 150 KB (WI_RXBUFSIZE = 153600), so an unauthenticated attacker who can reach the repeater HTTP port (default TCP 80) can overflow hdrbuf by at least 500 bytes with a single HTTP request containing a URI of 1500 bytes or longer, corrupting adjacent .bss-segment globals. The overflow occurs before any authentication check, making it reachable without credentials. A remote, unauthenticated attacker can achieve arbitrary code execution on the host running the repeater.