CVE-2026-51538 Auth bypass in n/a

Critical 9.1 Published 13 Jul 2026 Updated 14 Jul 2026

Attackers can hijack sessions by reusing valid handles from other clients, bypassing access controls in OpENer industrial protocol stacks.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2026-51538?

CVE-2026-51538 is a critical authentication bypass vulnerability in n/a, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

EIPStackGroup OpENer 2.3.0 (commit 76b95cf) suffers from an Incorrect Access Control vulnerability in its handling of encapsulation sessions. When the server processes critical encapsulation commands, it verifies whether the provided session_handle exists in the global session list, but it fails to verify whether that handle belongs to the specific TCP connection issuing the request. Because there is no strong binding between a session handle and its originating socket, any attacker on the network can use a valid session handle created by another legitimate client to bypass access controls.

Weakness: CWE-284

Which versions are affected by CVE-2026-51538?

It affects 1 product.

Products include Opener Project Opener.

How do I fix CVE-2026-51538?

No fix has been published for CVE-2026-51538 yet. Limit exposure of the affected software until one is available.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2026-51538 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-51538 exists.

Sources

Also known as GHSA-jcwf-w8h2-gq3f.