CVE-2026-67855Public exploitNetwork attack vector

Remote server crash via duplicate delayed callback

Published Aug 4, 2026 · Updated Aug 4, 2026

Heap use-after-free in open62541 GDS PushManagement allows remote attackers to crash enabled OPC UA servers with a crafted CallRequest. applyChangesToServer() queues the same transaction->dc node twice when one request invokes ApplyChanges twice, so secureChannel_delayedClose() frees and then dereferences its changes object. The vulnerable path requires a build with UA_ENABLE_GDS_PUSHMANAGEMENT enabled and yields a server-process crash, interrupted sessions, and failed certificate updates.

CVSS severity7.5
High
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap use-after-free in open62541 GDS PushManagement allows remote attackers to crash enabled OPC UA servers with a crafted CallRequest. applyChangesToServer() queues the same transaction->dc node twice when one request invokes ApplyChanges twice, so secureChannel_delayedClose() frees and then dereferences its changes object. The vulnerable path requires a build with UA_ENABLE_GDS_PUSHMANAGEMENT enabled and yields a server-process crash, interrupted sessions, and failed certificate updates.

The record

CVE
CVE-2026-67855
Published
Aug 4, 2026
Updated
Aug 4, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-400, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 4, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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