CVE-2026-128321

Unrated0% EPSS

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.

Published 2026-11-13 · last modified 2026-11-13

Full record at NVD ↗

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Ncerio by BeyondNets · data from NVD, CISA KEV, EPSS.