PatchTheCVECVE-2020-36891: A stored cross-site scripting vulnerability in Kentico Xperience allows attackers to upload files with spoofed
CVE-2020-36891 is a medium-severity flaw (CVSS 5.4) affecting xperience. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- No elevated risk signals yet
A fixed release or distro patch exists.
Risk facts
| CVSS score | 5.4 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Required |
| EPSS exploit chance | 0.2% (top 88%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2025-12-18 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2020-36891?
xperience: upgrade to newer than 12.0.49. Exact commands for each OS are on this page.
Is CVE-2020-36891 being exploited?
CVE-2020-36891 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2020-36891 affect?
CVE-2020-36891 affects xperience. Severity is medium (CVSS 5.4). 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 manipu
How urgent is CVE-2020-36891?
Priority 22/100. No elevated risk signals yet.
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