DEBIAN-CVE-2026-44988
LibVNCClient is a library for easy implementation of a VNC client. In 0.9.15 and earlier, LibVNCClient's Tight encoding decoder uses fixed-size 2048-pixel scratch buffers for the Gradient filter, but it does not reject Tight rectangles whose width is larger than 2048 pixels. A malicious VNC server can send a crafted FramebufferUpdate rectangle using Tight encoding with NoZlib | ExplicitFilter and the Gradient filter. When a LibVNCClient-based client connects, the client processes the server-controlled rectangle width and writes beyond fixed-size Gradient buffers. This vulnerability is fixed with commit 5b270544b85233668b98161323297d418a8f5fd1.
DEBIAN-CVE-2026-44988
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: osv:DEBIAN-CVE-2026-44988
libvncserver
Source reference: /affected/0/package/name
- Affected versions
- 0.9.14+dfsg-1
Source reference:
/affected/0/versions0.9.14+dfsg-1+deb12u1Source reference:
/affected/0/versions - Fixed versions
- 0.9.14+dfsg-1+deb12u2
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
libvncserver
Source reference: /affected/1/package/name
- Affected versions
- 0.9.15+dfsg-1
Source reference:
/affected/1/versions0.9.15+dfsg-1+deb13u1Source reference:
/affected/1/versions - Fixed versions
- 0.9.15+dfsg-1+deb13u2
Source reference:
/affected/1/ranges - Prerequisites
- Not stated in this record
libvncserver
Source reference: /affected/2/package/name
- Affected versions
- 0.9.15+dfsg-1
Source reference:
/affected/2/versions0.9.15+dfsg-2Source reference:
/affected/2/versions0.9.15+dfsg-3Source reference:
/affected/2/versions0.9.15+dfsg-4Source reference:
/affected/2/versions - Fixed versions
- 0.9.15+dfsg-5
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.9.14+dfsg-1+deb12u2"
}
]
}
],
"package": {
"name": "libvncserver",
"purl": "pkg:deb/debian/libvncserver?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"0.9.14+dfsg-1",
"0.9.14+dfsg-1+deb12u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44988.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.9.15+dfsg-1+deb13u2"
}
]
}
],
"package": {
"name": "libvncserver",
"purl": "pkg:deb/debian/libvncserver?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"0.9.15+dfsg-1",
"0.9.15+dfsg-1+deb13u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44988.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "0.9.15+dfsg-5"
}
]
}
],
"package": {
"name": "libvncserver",
"purl": "pkg:deb/debian/libvncserver?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"0.9.15+dfsg-1",
"0.9.15+dfsg-2",
"0.9.15+dfsg-3",
"0.9.15+dfsg-4"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-44988.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #56553 · Revision 1
- Added to Heist Feed
- Publisher date