CVE-2026-51538
EIPStackGroup OpENer Improper Session Authentication vulnerability
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.
INFO
Published Date :
July 13, 2026, 10:16 p.m.
Last Modified :
Aug. 11, 2026, 4:38 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Ensure session handles are strictly bound to originating TCP connections.
- Validate session ownership before processing encapsulation commands.
- Update EIPStackGroup OpENer to a patched version.
- Review access control logic for session management.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-51538.
| URL | Resource |
|---|---|
| https://gist.github.com/MrAlaskan/8156ca3acd6754a9f66efede0a1351f2 | Third Party Advisory |
| https://github.com/EIPStackGroup/OpENer/issues/565 | Exploit Issue Tracking Vendor Advisory |
| https://github.com/EIPStackGroup/OpENer/issues/565 | Exploit Issue Tracking Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-51538 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-51538
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-51538 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-51538 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 11, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:opener_project:opener:2.3.0:*:*:*:*:*:*:* Added Reference Type MITRE: https://gist.github.com/MrAlaskan/8156ca3acd6754a9f66efede0a1351f2 Types: Third Party Advisory Added Reference Type MITRE: https://github.com/EIPStackGroup/OpENer/issues/565 Types: Exploit, Issue Tracking, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/EIPStackGroup/OpENer/issues/565 Types: Exploit, Issue Tracking, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 14, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-284 Added Reference https://github.com/EIPStackGroup/OpENer/issues/565 Added SSVC {'id': 'CVE-2026-51538', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-14T13:13:55.072060Z'} -
New CVE Received by [email protected]
Jul. 13, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'n/a', 'product': 'n/a', 'versions': [{'status': 'affected', 'version': 'n/a'}]}] Added 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. Added Reference https://gist.github.com/MrAlaskan/8156ca3acd6754a9f66efede0a1351f2 Added Reference https://github.com/EIPStackGroup/OpENer/issues/565