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.
- Exploited
- No known exploitation
- Fix
- No fix listed
- Who is exposed
- Not reported
- 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.
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- Published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 30/100 · provisional
- How many real-world setups can hit the bug, from the vendor's advisory and CISA data. It does not know your setup.What do these mean? →
- Unclear
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- 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
- CVE published
- First seen by cve.now
Affected versions
- libwebsockets libwebsockets
Version range not reported
Evidence 2
- Advisory
- Link
Corrections
None so far.
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