NULL pointer dereference in LibVNCServer - CVE-2026-32854
Published: April 27, 2026
Vulnerability identifier: #VU128149
CSH Severity: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-32854
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
LibVNCServer
LibVNCServer
Software vendor:
LibVNC
LibVNC
Description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to null pointer dereference in httpProcessInput in src/libvncserver/httpd.c when handling malformed CONNECT or GET requests to the HTTP proxy handlers. A remote attacker can send a specially crafted request to cause a denial of service.
Only configurations with both the non-default -httpd and -enablehttpproxy options enabled are vulnerable.
Remediation
Install security update from vendor's website.