GlavSoft TightVNC up to 2.8.87 ZRLE decoder readPaletteRleTile out-of-bounds

Summaryinfo

A vulnerability was found in GlavSoft TightVNC up to 2.8.87. It has been rated as critical. This affects the function readPaletteRleTile of the component ZRLE decoder. Performing a manipulation results in out-of-bounds. This vulnerability is identified as CVE-2026-107611. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in GlavSoft TightVNC up to 2.8.87. It has been classified as critical. This affects the function readPaletteRleTile of the component ZRLE decoder. The manipulation with an unknown input leads to a out-of-bounds vulnerability. CWE is classifying the issue as CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at sourceforge.net. This vulnerability is uniquely identified as CVE-2026-107611 since 10/08/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details are known, but no exploit is available.

Upgrading to version 2.8.88 eliminates this vulnerability.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• GlavSoft

Name

• TightVNC

Version

• 2.8.0
• 2.8.1
• 2.8.2
• 2.8.3
• 2.8.4
• 2.8.5
• 2.8.6
• 2.8.7
• 2.8.8
• 2.8.9
• 2.8.10
• 2.8.11
• 2.8.12
• 2.8.13
• 2.8.14
• 2.8.15
• 2.8.16
• 2.8.17
• 2.8.18
• 2.8.19
• 2.8.20
• 2.8.21
• 2.8.22
• 2.8.23
• 2.8.24
• 2.8.25
• 2.8.26
• 2.8.27
• 2.8.28
• 2.8.29
• 2.8.30
• 2.8.31
• 2.8.32
• 2.8.33
• 2.8.34
• 2.8.35
• 2.8.36
• 2.8.37
• 2.8.38
• 2.8.39
• 2.8.40
• 2.8.41
• 2.8.42
• 2.8.43
• 2.8.44
• 2.8.45
• 2.8.46
• 2.8.47
• 2.8.48
• 2.8.49
• 2.8.50
• 2.8.51
• 2.8.52
• 2.8.53
• 2.8.54
• 2.8.55
• 2.8.56
• 2.8.57
• 2.8.58
• 2.8.59
• 2.8.60
• 2.8.61
• 2.8.62
• 2.8.63
• 2.8.64
• 2.8.65
• 2.8.66
• 2.8.67
• 2.8.68
• 2.8.69
• 2.8.70
• 2.8.71
• 2.8.72
• 2.8.73
• 2.8.74
• 2.8.75
• 2.8.76
• 2.8.77
• 2.8.78
• 2.8.79
• 2.8.80
• 2.8.81
• 2.8.82
• 2.8.83
• 2.8.84
• 2.8.85
• 2.8.86
• 2.8.87

CPE 2.3info

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CPE 2.2info

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Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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