LibVNCClient Tight Gradient decoding allows malicious server-triggered heap/stack OOB writes (LibVNC libvncserver)

CVE-2026-44988
HIGH 8.8

En bref

Source
NVD
EPSS
EPSS 0.24 % · centile 15 ()
État
PUBLISHED
Publiée
Mise à jour
Attribuée par
GitHub_M
Statut NVD
Awaiting Analysis

Description

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.

Faiblesses (CWE)

Références

Scores

VersionScoreVecteurÉvalué par
CVSS 3.1HIGH 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HGitHub_M
CVSS 3.1HIGH 8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:HNVD · security-advisories@github.com (Secondary)

Références européennes

Produits affectés

ProduitVersions
LibVNC · libvncserveraffected <= 0.9.15

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD