CVE-2026-107611: high-severity vulnerability in GlavSoft TightVNC
Out-of-bounds read in TightVNC Viewer ZRLE palette decoding
Published
18Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.1
exploitation probability
—
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
Affected products
GlavSoft · TightVNCRelated CVEs — GlavSoft TightVNC
In the same product, most dangerous first.
CVE-2026-107615HIGHDLL search order hijacking via screenhooks libraries in TightVNC ServerEPSS —CVE-2026-107614MEDIUMInteger underflow in TightVNC Server cursor shape trimming leads to out-of-bounds readEPSS —CVE-2026-107613MEDIUMNULL pointer dereference in TightVNC Server Win8ScreenDriver after failed DXGI re-initializationEPSS —CVE-2026-107612HIGHWorld-accessible IPC shared memory with predictable name in TightVNC ServerEPSS —