Server crash via forged HistoryRead continuation point
Published Aug 4, 2026 · Updated Aug 4, 2026
Heap-based buffer overflow in open62541 1.5.5 allows remote attackers to crash OPC UA servers through a crafted HistoryRead continuation point. getHistoryData_service_default decodes a client-controlled skip value whose size_t subtraction wraps, then gives the memory backend a copy limit larger than the allocated UA_DataValue array. Exploitation requires historizing, the default history database, the memory backend, and an exposed historized node; the confirmed consequence is a server-process abort.
Summary
What happened
Heap-based buffer overflow in open62541 1.5.5 allows remote attackers to crash OPC UA servers through a crafted HistoryRead continuation point. getHistoryData_service_default decodes a client-controlled skip value whose size_t subtraction wraps, then gives the memory backend a copy limit larger than the allocated UA_DataValue array. Exploitation requires historizing, the default history database, the memory backend, and an exposed historized node; the confirmed consequence is a server-process abort.
The record
- CVE
- CVE-2026-67860
- Published
- Aug 4, 2026
- Updated
- Aug 4, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-122, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 4, 2026CVE publishedPublication date reported by the CVE source.
- Aug 4, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- HistoryRead continuation-point PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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