Integer underflow in TightVNC Server cursor shape trimming leads to out-of-bounds read
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.
CVE-2026-107614
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-107614
TightVNC
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "GlavSoft",
"modules": [
"TightVNC Server (cursor shape processing)"
],
"product": "TightVNC",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "2.8.88",
"versionType": "custom"
}
],
"platforms": [
"Windows"
],
"programFiles": [
"WinCursorShapeUtils.cpp"
],
"defaultStatus": "unaffected",
"programRoutines": [
{
"name": "WinCursorShapeUtils::trimTransparent()"
},
{
"name": "getCursorHeight()"
}
]
}
]- Related CVEs
- CVE-2026-107614
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #12508 · Revision 1
- Added to Heist Feed
- Publisher date