OESA-2026-2565

Source
https://www.openeuler.org/en/security/security-bulletins/detail/?id=openEuler-SA-2026-2565
Import Source
https://repo.openeuler.org/security/data/osv/OESA-2026-2565.json
JSON Data
https://api.osv.dev/v1/vulns/OESA-2026-2565
Upstream
Published
2026-06-05T15:48:46Z
Modified
2026-06-05T16:00:40.121808070Z
Summary
libvncserver security update
Details

libvncserver is a set of programs using the RFB (Remote Frame Buffer) protocol. They are designed to "export" a frame buffer via net: you set up a server and can connect to it via VNC viewers. If the server supports WebSockets (which LibVNCServer does), you can also connect using an in-browser VNC viewer like noVNC. It is already in wide use for administration, but it is not that easy to program a server yourself.

Security Fix(es):

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.(CVE-2026-44988)

Database specific
{
    "severity": "High"
}
References

Affected packages

openEuler:22.03-LTS-SP4 / libvncserver

Package

Name
libvncserver
Purl
pkg:rpm/openEuler/libvncserver&distro=openEuler-22.03-LTS-SP4

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
0.9.13-5.oe2203sp4

Ecosystem specific

{
    "aarch64": [
        "libvncserver-0.9.13-5.oe2203sp4.aarch64.rpm",
        "libvncserver-debuginfo-0.9.13-5.oe2203sp4.aarch64.rpm",
        "libvncserver-debugsource-0.9.13-5.oe2203sp4.aarch64.rpm",
        "libvncserver-devel-0.9.13-5.oe2203sp4.aarch64.rpm"
    ],
    "src": [
        "libvncserver-0.9.13-5.oe2203sp4.src.rpm"
    ],
    "x86_64": [
        "libvncserver-0.9.13-5.oe2203sp4.x86_64.rpm",
        "libvncserver-debuginfo-0.9.13-5.oe2203sp4.x86_64.rpm",
        "libvncserver-debugsource-0.9.13-5.oe2203sp4.x86_64.rpm",
        "libvncserver-devel-0.9.13-5.oe2203sp4.x86_64.rpm"
    ]
}

Database specific

source
"https://repo.openeuler.org/security/data/osv/OESA-2026-2565.json"