# CVE-2026-67855: open62541 heap use-after-free in GDS PushManagement certificate update

Source: https://junglewise.ai/threats/cve-2026-67855-open62541-heap-use-after-free-in-gds-pushmanagement-certificate  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-04. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-67855 · Severity: high · CVSS 7.5 · Published 2026-08-04

open62541 is an open-source implementation of the OPC Unified Architecture (OPC UA) protocol, a widely-used industrial control system communication standard. A memory safety flaw in the Global Discovery Server (GDS) PushManagement certificate update feature allows a remote attacker to trigger a denial of service by crashing the server, disrupting operational technology environments that depend on OPC UA for equipment communication.

## Quick answers

**Is CVE-2026-67855 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-67855 being exploited in the wild.

**How severe is CVE-2026-67855?** High severity, with a CVSS score of 7.5, published 4 August 2026.

**Which products and versions are affected?** open62541 open62541 <UNKNOWN>.

**Is there a fix for CVE-2026-67855?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-67855 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-67855?** Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a heap use-after-free (CWE-416) in the GDS PushManagement certificate update workflow that occurs only when the UA_ENABLE_GDS_PUSHMANAGEMENT compile-time flag is enabled. A remote attacker can exploit this memory corruption issue over the network to trigger a crash, resulting in denial of service. The flaw affects the proper lifecycle management of heap-allocated objects during certificate update operations. No patch availability information is provided in the advisory; affected versions must be identified from the vendor's release history.

## Affected products

- open62541 open62541 <UNKNOWN>

## Timeline

- 2026-08-04: disclosed

## References

- [https://github.com/open62541/open62541](https://github.com/open62541/open62541)
- [https://github.com/open62541/open62541/blob/master/arch/posix/eventloop_posix.c](https://github.com/open62541/open62541/blob/master/arch/posix/eventloop_posix.c)