Use After Free Vulnerability in open62541 Client Types by o6
CVE-2026-18785

4.8MEDIUM

Key Information:

Vendor

O6

Status
Open62541
Vendor
CVE Published:
4 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-18785?

A vulnerability has been identified in the open62541 project that impacts the UA_Client_getRemoteDataTypes function within the custom_datatype client types implementation. This flaw allows for potential exploitation via a use after free attack, posing a significant risk when executed on a local host. The issue has been made public, prompting concerns over its potential for exploitation. It is crucial for users of the affected version to be vigilant and consider applying mitigations, as the project developers have closed the issue report without an official security vulnerability submission process.

Affected Version(s)

open62541 ca356b088ada7dee824d1b4acd07c1ff07ce242b

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-2026-18785 - Proof of Concept

References

https://vuldb.com/vuln/385787
vdb-entrytechnical-description
https://vuldb.com/vuln/385787/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-18785
third-party-advisory

CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Local
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

Chuan Wei (SCU)
VULL (VulDB User)
SCU_1CP (VulDB User)
VulDB CNA Team
.