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Vulnerability · Published Mar 24, 2026 · Assigned by VulnCheck

CVE-2026-32854LibVNCServer httpd proxy NULL Pointer Dereference

Medium 6.3

In plain English

A medium-severity null pointer dereference in LibVNCServer from LibVNC. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 5.4% (higher than 93% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.3Medium
Exploit odds (30 days)5.4%top 7.3% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

LibVNCServer versions 0.9.15 and prior (fixed in commit dc78dee) contain null pointer dereference vulnerabilities in the HTTP proxy handlers within httpProcessInput() in httpd.c that allow remote attackers to cause a denial of service by sending specially crafted HTTP requests. Attackers can exploit missing validation of strchr() return values in the CONNECT and GET proxy handling paths to trigger null pointer dereferences and crash the server when httpd and proxy features are enabled.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12libvncserver0.9.14+dfsg-1+deb12u1DEBIAN-CVE-2026-32854
Debian:13libvncserver0.9.15+dfsg-1+deb13u1DEBIAN-CVE-2026-32854
Debian:14libvncserver0.9.15+dfsg-3DEBIAN-CVE-2026-32854
Ubuntu:22.04:LTSlibvncserver0.9.13+dfsg-3ubuntu0.1USN-8463-1
Ubuntu:22.04:LTSlibvncserver0.9.13+dfsg-3ubuntu0.1UBUNTU-CVE-2026-32854
Ubuntu:24.04:LTSlibvncserver0.9.14+dfsg-1ubuntu0.1USN-8463-1
Ubuntu:24.04:LTSlibvncserver0.9.14+dfsg-1ubuntu0.1UBUNTU-CVE-2026-32854
Ubuntu:25.10libvncserver0.9.15+dfsg-1ubuntu0.1USN-8463-1
Ubuntu:25.10libvncserver0.9.15+dfsg-1ubuntu0.1UBUNTU-CVE-2026-32854
Ubuntu:26.04:LTSlibvncserver0.9.15+dfsg-3ubuntu0.1USN-8463-1
Ubuntu:22.04:LTStightvncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:24.04:LTStightvncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:25.10tightvncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:26.04:LTStightvncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:26.10tightvncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:22.04:LTSveyonno fix listedUBUNTU-CVE-2026-32854
Ubuntu:24.04:LTSveyonno fix listedUBUNTU-CVE-2026-32854
Ubuntu:25.10veyonno fix listedUBUNTU-CVE-2026-32854
Ubuntu:26.04:LTSveyonno fix listedUBUNTU-CVE-2026-32854
Ubuntu:26.10veyonno fix listedUBUNTU-CVE-2026-32854
Ubuntu:22.04:LTSvinono fix listedUBUNTU-CVE-2026-32854
Ubuntu:24.04:LTSvinono fix listedUBUNTU-CVE-2026-32854
Ubuntu:25.10vinono fix listedUBUNTU-CVE-2026-32854
Ubuntu:22.04:LTSx11vncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:24.04:LTSx11vncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:25.10x11vncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:26.04:LTSx11vncno fix listedUBUNTU-CVE-2026-32854
Ubuntu:26.10x11vncno fix listedUBUNTU-CVE-2026-32854

Affected products (as reported)

VendorProductVersions
LibVNC LibVNCServer 0 – through 0.9.15

Weakness: CWE-476 · Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

References