Server crash via recursive ObjectType instantiation
Published Aug 5, 2026 · Updated Aug 5, 2026
Uncontrolled recursion in open62541 1.5.5 and earlier allows remote attackers to crash an OPC UA server through NodeManagement requests. NodeManagement accepts a mandatory child whose TypeDefinition points back to its parent ObjectType, while addTypeChildren recursively expands it without cycle detection or a depth guard. Access to AddNodes and AddReferences is required; successful exploitation exhausts the process stack and terminates the server.
Summary
What happened
Uncontrolled recursion in open62541 1.5.5 and earlier allows remote attackers to crash an OPC UA server through NodeManagement requests. NodeManagement accepts a mandatory child whose TypeDefinition points back to its parent ObjectType, while addTypeChildren recursively expands it without cycle detection or a depth guard. Access to AddNodes and AddReferences is required; successful exploitation exhausts the process stack and terminates the server.
The record
- CVE
- CVE-2026-67864
- Published
- Aug 5, 2026
- Updated
- Aug 5, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-400, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 5, 2026CVE publishedPublication date reported by the CVE source.
- Aug 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Self-referential ObjectType instantiation PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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