How severe is CVE-2020-36891?

CVE-2020-36891 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-36891 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-36891?

CVE-2020-36891 affects Kentico Xperience. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-36891?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2020-36891 have an EU (EUVD) identifier?

Yes. CVE-2020-36891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204371.

When was CVE-2020-36891 published?

CVE-2020-36891 was published on 2025-12-18 and last updated on 2026-06-17.

CVE-2020-36891

CVE-2020-36891 is a medium-severity vulnerability in Kentico Xperience with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
CVSS v4: 5.1
EPSS exploit prediction: 0% (8th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-204371
Weakness: CWE-79
Affected product: Kentico Xperience
Published: 2025-12-18
Last modified: 2026-06-17

Description

A stored cross-site scripting vulnerability in Kentico Xperience allows attackers to upload files with spoofed Content-Type that do not match file extensions. Attackers can exploit this vulnerability by uploading malicious files with manipulated MIME types, allowing malicious scripts to execute in users' browsers.

Frequently asked questions

What is CVE-2020-36891?: A stored cross-site scripting vulnerability in Kentico Xperience allows attackers to upload files with spoofed Content-Type that do not match file extensions. Attackers can exploit this vulnerability by uploading malicious files with manipulated MIME types, allowing malicious scripts to execute in users' browsers.
How severe is CVE-2020-36891?: CVE-2020-36891 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-36891 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-36891?: CVE-2020-36891 affects Kentico Xperience. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-36891?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2020-36891 have an EU (EUVD) identifier?: Yes. CVE-2020-36891 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-204371.
When was CVE-2020-36891 published?: CVE-2020-36891 was published on 2025-12-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:kentico:xperience:*:*:*:*:*:*:*:*

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