PT-2026-27460 · Libvnc · Libvncserver

Published 2026-03-24 · Updated 2026-03-24 · CVE-2026-32853

Mitre

CVSS v4.0

6.9

Medium

AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N

LibVNCServer versions 0.9.15 and prior (fixed in commit 009008e) contain a heap out-of-bounds read vulnerability in the UltraZip encoding handler that allows a malicious VNC server to cause information disclosure or application crash. Attackers can exploit improper bounds checking in the HandleUltraZipBPP() function by manipulating subrectangle header counts to read beyond the allocated heap buffer.

Fix

Out of bounds Read

Weakness Enumeration

CWE-125

Related Identifiers

CVE-2026-32853

Affected Products

Libvncserver

References · 4

• https://github.com/LibVNC/libvncserver/commit/009008e2f4d5a54dd71f422070df3af7b3dbc931 · Patch
• https://github.com/LibVNC/libvncserver/security/advisories/GHSA-87q7-v983-qwcj · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-32853 · Security Note
• https://vulncheck.com/advisories/libvncserver-ultrazip-encoding-heap-out-of-bounds-read · Note