CVE-2026-32853 MEDIUM

CVE-2026-32853: LibVNCServer UltraZip Encoding Heap Out-of-bounds Read

Vendor Libvnc
Product LibVNCServer
Weakness CWE-125
Published March 24, 2026
Last update March 25, 2026

CVSS base score

6.9/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 24, 2026 CVE published
March 25, 2026 Record updated