CVE-2026-32854Public exploitNetwork attack vector

Unauthenticated server crash via malformed proxy requests

Published Mar 24, 2026 · Updated Mar 24, 2026

NULL pointer dereferences in LibVNCServer 0.9.15 and earlier allow remote attackers to crash VNC servers via malformed HTTP requests. The httpProcessInput function passes unchecked strchr() results from colon-less CONNECT and slash-less GET requests to atoi() or strncmp(), causing a segmentation fault. Exploitation requires both non-default HTTP daemon and HTTP proxy options, and repeated requests can repeatedly interrupt the embedded server process.

CVSS severity6.3
Medium
EPSS probability5.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

NULL pointer dereferences in LibVNCServer 0.9.15 and earlier allow remote attackers to crash VNC servers via malformed HTTP requests. The httpProcessInput function passes unchecked strchr() results from colon-less CONNECT and slash-less GET requests to atoi() or strncmp(), causing a segmentation fault. Exploitation requires both non-default HTTP daemon and HTTP proxy options, and repeated requests can repeatedly interrupt the embedded server process.

The record

CVE
CVE-2026-32854
Published
Mar 24, 2026
Updated
Mar 24, 2026
Vendor
LibVNC
Product
LibVNCServer
Classifications
CWE-476, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.9.15

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

LibVNC · LibVNCServerversion=0 <=0.9.15

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
6.3LibVNC GitHub Security AdvisoryCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo