CVE-2026-114550
libwebsockets MQTT Protocol PUBACK Packet Handling Out-Of-Bounds Write Remote Code Execution Vulnerability
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.
Fixes and workarounds
No remediation reported in collected sources.
Missing remediation information is not evidence that no patch exists.
Affected products and versions
| Product | Versions | Authority |
|---|---|---|
| libwebsockets libwebsockets |
b4b5aed3903eaff09cd76a410f69bbe5dff66f8e (affected)
Other versions: unknown |
CNA: zdi |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.0 / 8.1 high |
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H | CNA: zdi |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://www.zerodayinitiative.com/advisories/ZDI-26-792/CNA: zdi · x_research-advisory
- https://github.com/warmcat/libwebsockets/commit/c9e8e1834d7f13038c82963086b90e2ee9c5b44cCNA: zdi · vendor-advisory
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