How severe is CVE-2021-36581?

CVE-2021-36581 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-2021-36581 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-36581?

CVE-2021-36581 affects Kooboo Kooboo Cms. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-36581?

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-2021-36581 published?

CVE-2021-36581 was published on 2021-09-14 and last updated on 2026-07-05.

CVE-2021-36581

CVE-2021-36581 is a critical-severity vulnerability in Kooboo Kooboo Cms 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 v2: 7.5
EPSS exploit prediction: 2% (72nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-434
Affected product: Kooboo Kooboo Cms
Published: 2021-09-14
Last modified: 2026-07-05

Description

Kooboo CMS 2.1.1.0 is vulnerable to Insecure file upload. It is possible to upload any file extension to the server. The server does not verify the extension of the file and the tester was able to upload an aspx to the server.

Frequently asked questions

What is CVE-2021-36581?: Kooboo CMS 2.1.1.0 is vulnerable to Insecure file upload. It is possible to upload any file extension to the server. The server does not verify the extension of the file and the tester was able to upload an aspx to the server.
How severe is CVE-2021-36581?: CVE-2021-36581 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-2021-36581 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (72nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-36581?: CVE-2021-36581 affects Kooboo Kooboo Cms. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-36581?: 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-2021-36581 published?: CVE-2021-36581 was published on 2021-09-14 and last updated on 2026-07-05.

References

Affected products (1)

cpe:2.3:a:kooboo:kooboo_cms:2.1.1.0:*:*:*:*:*:*:*

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