Improper Input Validation in WebSocket Frame Parser of Facil.io by Boaz Segev
CVE-2026-16632

6.9MEDIUM

Key Information:

Vendor

Boazsegev

Status
Facil.io
Vendor
CVE Published:
22 July 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-16632?

A vulnerability has been identified in the facil.io library, affecting versions up to 0.7.4. The flaw resides in the websocket_on_protocol_error function located in the websocket_parser.h file. This vulnerability arises from improper input validation when manipulating the argument on_message, allowing a potential remote attacker to exploit it. Despite a report made regarding this issue, the project maintainers have yet to respond. As a result, users of this library are advised to review their systems' implementations and remain vigilant.

Affected Version(s)

facil.io 0.7.0

facil.io 0.7.1

facil.io 0.7.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-16632 - Proof of Concept

References

https://vuldb.com/vuln/382382
vdb-entrytechnical-description
https://vuldb.com/vuln/382382/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-16632
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Fantasy_2026 (VulDB User)
VulDB CNA Team
.