libvncserver: LibVNCClient is a library for easy implementation of a VNC client
CVE-2026-44988 is fixed in 4 products on 1 platform, first by libvncclient1 0.9.15+dfsg-3ubuntu0.1, released May 27, 2026. It is not reported as exploited. Patch Radar priority: High.
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.
Where it's fixed
| Product | Fixed in | Fix | Released |
|---|---|---|---|
| Linux | |||
| LibVNCServer · opensuse-leap 16.0 | 0.9.14-160000.5.1 | OPENSUSE-SU-2026:21118-1 | Jun 20, 2026 |
| LibVNCServer · sles 15.7 | 0.9.14-150600.3.9.1 | SUSE-SU-2026:2427-1 | Jun 17, 2026 |
| LibVNCServer · sles 16.0 | 0.9.14-160000.5.1 | SUSE-SU-2026:22190-1 | Jun 20, 2026 |
| libvncclient1 · Ubuntu 22.04.1 LTS (jammy) | 0.9.13+dfsg-3ubuntu0.1 | libvncclient1 0.9.13+dfsg-3ubuntu0.1 | Jun 24, 2026 |
| libvncclient1 · Ubuntu 24.04.5 LTS (noble) | 0.9.14+dfsg-1ubuntu0.1 | libvncclient1 0.9.14+dfsg-1ubuntu0.1 | Jun 24, 2026 |
| libvncclient1 · Ubuntu 25.10 (questing) | 0.9.15+dfsg-1ubuntu0.1 | libvncclient1 0.9.15+dfsg-1ubuntu0.1 | Jun 24, 2026 |
| libvncclient1 · Ubuntu 26.04.1 LTS (resolute) | 0.9.15+dfsg-3ubuntu0.1 | libvncclient1 0.9.15+dfsg-3ubuntu0.1 | May 27, 2026 |
| libvncserver · Debian 12.15 (bookworm) | 0.9.14+dfsg-1+deb12u2 | DEBIAN-CVE-2026-44988 | Jun 24, 2026 |
| libvncserver · Debian 13.5 (trixie) | 0.9.15+dfsg-1+deb13u2 | DEBIAN-CVE-2026-44988 | Jun 24, 2026 |
| libvncserver · Debian 14 | 0.9.15+dfsg-5 | DEBIAN-CVE-2026-44988 | Jun 24, 2026 |
| libvncserver1 · Ubuntu 22.04.1 LTS (jammy) | 0.9.13+dfsg-3ubuntu0.1 | libvncserver1 0.9.13+dfsg-3ubuntu0.1 | Jun 24, 2026 |
| libvncserver1 · Ubuntu 24.04.5 LTS (noble) | 0.9.14+dfsg-1ubuntu0.1 | libvncserver1 0.9.14+dfsg-1ubuntu0.1 | Jun 24, 2026 |
| libvncserver1 · Ubuntu 25.10 (questing) | 0.9.15+dfsg-1ubuntu0.1 | libvncserver1 0.9.15+dfsg-1ubuntu0.1 | Jun 24, 2026 |
| libvncserver1 · Ubuntu 26.04.1 LTS (resolute) | 0.9.15+dfsg-3ubuntu0.1 | libvncserver1 0.9.15+dfsg-3ubuntu0.1 | May 27, 2026 |
Patch Radar data is free to use with attribution. Terms and how to credit it.
Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.