CVE-2026-21806
HCL BigFix Service Management was affected with Admin Session Concurrency vulnerability (CVE-2026-21806)
Description
HCL BigFix Service Management is affected by an Administrative Session Concurrency vulnerability. The application allows multiple simultaneous authenticated sessions for the same administrative account, which could enable an unauthorized attacker to predict or hijack valid session identifiers. Successful exploitation allows an attacker to compromise affected administrative sessions and execute actions with full privileged user permissions.
INFO
Published Date :
Sept. 18, 2026, 12:17 p.m.
Last Modified :
Sept. 18, 2026, 1:44 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-21806
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | LOW | 1e47fe04-f25f-42fa-b674-36de2c5e3cfc | ||||
| CVSS 3.1 | LOW | [email protected] |
Solution
- Enforce single active session per administrative account.
- Implement session timeout for inactivity.
- Invalidate old sessions upon new login.
- Monitor for suspicious session activity.
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-2026-21806.
| URL | Resource |
|---|---|
| https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0133592 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-21806 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-2026-21806
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-2026-21806 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-21806 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.
-
New CVE Received by [email protected]
Sep. 18, 2026
Action Type Old Value New Value Added Description HCL BigFix Service Management is affected by an Administrative Session Concurrency vulnerability. The application allows multiple simultaneous authenticated sessions for the same administrative account, which could enable an unauthorized attacker to predict or hijack valid session identifiers. Successful exploitation allows an attacker to compromise affected administrative sessions and execute actions with full privileged user permissions. Added CVSS V3.1 AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Added CWE CWE-557 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/21xxx/CVE-2026-21806.json">CVE-2026-21806</a> Added Reference https://support.hcl-software.com/csm?id=kb_article&sysparm_article=KB0133592