CVE-2025-5591Network attack vector

Session hijacking via unencoded stored form input

Published Jan 5, 2026 · Updated Jan 5, 2026

Stored XSS in Kentico Xperience 13 before 13.0.167 allows remote attackers to execute script in a victim's session via form input. The form component stores attacker-controlled markup and later renders it without applying the documented HTMLEncode operation. The victim must view the affected content; script execution can hijack that session and perform actions available to it.

CVSS severity5.4
Medium
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Kentico Xperience 13 before 13.0.167 allows remote attackers to execute script in a victim's session via form input. The form component stores attacker-controlled markup and later renders it without applying the documented HTMLEncode operation. The victim must view the affected content; script execution can hijack that session and perform actions available to it.

The record

CVE
CVE-2025-5591
Published
Jan 5, 2026
Updated
Jan 5, 2026
Vendor
Kentico
Product
Kentico Xperience 13
Classifications
CWE-79, CWE-1188, CAPEC-593, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 5, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 5, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=13.0.167

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Kentico · Kentico Xperience 13version=13.0.167

Published CVSS scores

7.7The Missing Link AustraliaCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U
5.4NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-1188Insecure Default Initialization of Resource
CAPEC-593Session Hijacking
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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