CVE-2026-114550

Read full 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.

CVSS 8.1 (HIGH)

Attention and evidence

HYPE SCORE

0.3/10

REALITY · THREAT PRIORITY

2.9/10

General review priority; not probability

Evidence confidence: Insufficient evidence

Why this priority?

Technical severity: CVSS 8.1: +2.83
Fresh EPSS: 0.84%: +0.02

General review priority, not probability, victim count or asset-specific risk. A range covers missing CVSS/EPSS inputs within the current evidence state.

Sources: 2 documents and public datasets.

Hype components

Headline sample (25%)

0/100

Press, 30 days (60%)

5/100

Grounded branding (15%)

0/100

HYPE TOTAL3/100

Sources and documents

ZDI: Published Advisories

Technical advisory · 26 Oct 2026, 05:00 · ZDI-26-792: libwebsockets MQTT Protocol PUBACK Packet Handling Out-Of-Bounds Write Remote Code Execution Vulnerability

ZDI: Published Advisories

Press · 26 Oct 2026, 05:00 · ZDI-26-792: libwebsockets MQTT Protocol PUBACK Packet Handling Out-Of-Bounds Write Remote Code Execution Vulnerability

Score evolution

● Hype ● Reality

━ Hype Score (Perceived) ━ Reality threat priority. Definition changes are not new attacks.

Public exploit evidence

Public exploit entries / repo candidates

Evidence context and dated references

Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs. Published 2 days ago. Exploitation evidence usually takes weeks to show up: a low reality score can mean there is no data yet, not that the flaw is mild.

Evidence in context

Confidence in exploitation evidence: Insufficient evidence
Priority basis: Exploitation in attacks unconfirmed; CVSS 8.1; EPSS 0.8%
Attention, last 30 days: 1 distinct story titles; 1 press documents; 1 publisher domains.
Technical potential: network access, no prior privileges, no user interaction, additional attack conditions.
Observed activity: No exploitation observation is recorded.
Known scale: Not quantified.
Evidence confidence basis: Insufficient evidence

Score evaluated: 2026-11-05 13:59:54.760909+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z

Source event timeline

First press mention

26 Oct 2026, 05:00

Latest press mention

26 Oct 2026, 05:00

Published

03 Nov 2026, 23:47

Score calculated

05 Nov 2026, 13:59