Medium · CVSS 6.1CVE-2026-107614

Integer underflow in TightVNC Server cursor shape trimming leads to out-of-bounds readCVE-2026-107614

Answer in brief

CVE-2026-107614 records a Medium severity (CVSS 6.1) vulnerability in Integer underflow in TightVNC Server cursor shape trimming leads to out-of-bounds read. The current sources do not mark it as known exploited. The current feed maps GlavSoft/TightVNC (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 8, 2026Updated Oct 8, 2026Source checked Oct 8, 2026First seen by HOL Oct 8, 2026Material review Oct 8, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 6.1
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 6.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps GlavSoft/TightVNC (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
GlavSoft/TightVNCgeneric	>=0 <2.8.88	2.8.88

Recommended response

Check inventory. Check lockfiles and deployed manifests for GlavSoft/TightVNC.
Review the reported fix. Source-reported solution: Upgrade TightVNC for Windows to version 2.8.88 or later.

Evidence timeline and material changes

Published upstream
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 8, 2026

Sources and claim methodology

Upstream source description

An integer underflow in WinCursorShapeUtils::trimTransparent() in GlavSoft TightVNC Server for Windows before 2.8.88 allows a local authenticated user to crash the server, and potentially read out-of-bounds memory, by causing a cursor shape with a width or height of zero to be processed on the DXGI capture path. The loop bound width - 1 wraps to 0xFFFFFFFF, producing an access roughly 4 GB beyond the 64 KB cursor buffer; a monochrome cursor of height 1 also becomes 0 because getCursorHeight() halves the height in place.

Quoted source text, attributed separately from HOL analysis.