9.8

CVE-2026-21806

CVSS: 9.8v3.1CriticalAnalyzed
Published 2026-09-18Last modified 2026-09-18
Open JSON

Vulnerability summary

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.8/10
010
Critical · v3.1 (nvd)
EPSS score
0.15%
0%100%
Low · Change unavailable
KEVNot listed0 of 3 catalogs
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 2026-09-18
    PublishedVulnerability first disclosed.
  2. 2026-09-18
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

2026-09-192026-10-14
EPSS score
0.15%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Hcl software1 product
  • hcl bigfix service managementVersion 27
Hcltech1 product
  • bigfix_service_management27

2 vendors · 2 products

References

1 links