How severe is CVE-2026-21662?

CVE-2026-21662 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-21662 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21662?

CVE-2026-21662 affects Johnsoncontrols Fms Employee. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21662?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-21662 published?

CVE-2026-21662 was published on 2026-07-31 and last updated on 2026-08-10.

CVE-2026-21662

CVE-2026-21662 is a critical-severity vulnerability in Johnsoncontrols Fms Employee with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-434.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 4.8
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Johnsoncontrols Fms Employee
Published: 2026-07-31
Last modified: 2026-08-10

Description

Unrestricted upload of file with dangerous type vulnerability in Johnson Controls FM Systems Employee allows Using Malicious Files. This issue affects FM Systems Employee: before 2025.3.1.

Frequently asked questions

What is CVE-2026-21662?: Unrestricted upload of file with dangerous type vulnerability in Johnson Controls FM Systems Employee allows Using Malicious Files. This issue affects FM Systems Employee: before 2025.3.1.
How severe is CVE-2026-21662?: CVE-2026-21662 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-21662 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21662?: CVE-2026-21662 affects Johnsoncontrols Fms Employee. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21662?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-21662 published?: CVE-2026-21662 was published on 2026-07-31 and last updated on 2026-08-10.

References

https://www.johnsoncontrols.com/trust-center/cybersecurity/security-advisories

Affected products (1)

cpe:2.3:a:johnsoncontrols:fms_employee:*:*:*:*:*:*:*:*

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