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TI-2021-19747 Aliases CVE-2021-43991GHSA-r763-2x4q-j7xx

Persistent XSS via Avatar Upload in Kentico Xperience CMS

Priority LOW 31CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

The Kentico Xperience CMS version 13.0 – 13.0.43 is vulnerable to a persistent Cross-Site Scripting (XSS) vulnerability (also known as Stored or Second-Order XSS). Persistent XSS vulnerabilities occur when the application stores and retrieves client supplied data without proper handling of dangerous content. This type of XSS vulnerability is exploited by submitting malicious script content to the application which is then retrieved and executed by other application users. The attacker could exploit this to conduct a range of attacks against users of the affected application such as session hijacking, account take over and accessing sensitive data.

Why it matters now

EPSS 0.00563 47th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed Kentico Xperience XMS (Kentico): 13.0.43

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
KenticoKentico Xperience XMS13.0 to before 13.0.4313.0.43Patch availableCNA
  • Kentico Xperience XMS VendorKentico Affected 13.0 to before 13.0.43 Fixed in 13.0.43 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:kentico:xperience:*:*:*:*:*:*:*:*13.0.0 – 13.0.43VulnerableKentico
  • cpe:2.3:a:kentico:xperience:*:*:*:*:*:*:*:* Versions 13.0.0 – 13.0.43 Vulnerable ·Kentico

Remediation

  • Fix · CNA Kentico Xperience XMS (Kentico) Fixed in 13.0.43

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-43991
  2. 2026-10-03 Alias added: GHSA-r763-2x4q-j7xx

References

Exploit 1

  • TI-2025-02400 Kentico Xperience <= 13.0.178 Staging Sync Server None Password Type Authentication Bypass KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-02399 Kentico Xperience <= 13.0.172 Staging Sync Server Digest Password Authentication Bypass KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-07394 An issue was discovered in Kentico 12.0.x before 12.0.15, 11.0.x before 11.0.48, 10.0.x… KEVCVSS 3.1CRITICAL 9.8
  • TI-2025-02402 Kentico Xperience <= 13.0.178 Staging Media File Upload Authenticated RCE KEVCVSS 3.1HIGH 7.2
  • TI-2025-23449 Unrestricted file upload in Kentico Xperience CVSS 3.1CRITICAL 9.8
  • TI-2017-12981 Kentico 9.0 before 9.0.51 and 10.0 before 10.0.48 allows remote attackers to obtain… CVSS 3.0CRITICAL 9.8
See all 49 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences