Skip to main content
← Vulnerabilities

libwebsockets MQTT Protocol PUBACK Packet Handling Out-Of-Bounds Write Remote Code Execution Vulnerability

Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.

8.1HighCNA
Exploited
No known exploitation
Fix
No fix listed
Who is exposed
Not reported
30Pcve.now Index 30 of 100 · methodology v3 · provisional
  • Exploitation?/40Exploitation: unknown (data gap). No CISA SSVC exploitation rating yet
  • Exposure17/25No login or user action needed, reachable over the network without a login · Data gap: Advisories don't say whether default setups are affected
  • Reach?/20Reach: unknown (data gap). No tracked technology or package matched
  • Severity8.1/10CVSS 8.1
  • No patch5/5No patch listed yet

What would change the score

  • Would score about 75 if added to CISA KEV
  • Would score about 70 if CISA's SSVC rates exploitation active
  • Would score about 35 if advisories confirm default setups are exposed

CVE-2026-114550 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 8.1 (high) and affects libwebsockets; no fixed version is listed yet.

Published
Last modified
Published
Not listed in CISA KEV
30/100 · provisional
Unclear
None on Exploit-DB, Metasploit or GitHub

Summary

The libwebsockets library, a widely used C library for WebSocket and MQTT communication, is affected when it handles MQTT PUBACK packets. An unauthenticated remote attacker could exploit a memory write flaw to run arbitrary code within the context of the affected process.

Read the original description

libwebsockets MQTT Protocol PUBACK Packet Handling Out-Of-Bounds Write Remote Code Execution Vulnerability. This vulnerability allows remote attackers to execute arbitrary code on affected installations of libwebsockets. Authentication is not required to exploit this vulnerability. The specific flaw exists within the handling of PUBACK packets. The issue results from the lack of proper validation of user-supplied data, which can result in a write past the end of an allocated buffer. An attacker can leverage this vulnerability to execute code in the context of the current process. Was ZDI-CAN-31039.

Timeline

  1. CVE published
  2. First seen by cve.now

Affected versions

  • libwebsockets libwebsockets

    Version range not reported

Evidence 2

  1. Advisory
  2. Link

Corrections

None so far.

Something wrong on this page? Report an error. Every fix is listed here.