CVE-2026-81898Network attack vector

Stored XSS via unescaped country-less Address labels

Published Sep 15, 2026 · Updated Sep 15, 2026

Stored XSS in Concrete CMS before 9.5.3 allows remote authenticated users to execute script in dashboard users' sessions. The country-less Address text formatter skips HTML escaping, and Express association templates echo the resulting label mask without applying h(). Exploitation requires permission to submit an Address attribute with a blank country and a dashboard user to open the affected entry, placing that user's session actions and data at risk.

CVSS severity7.5
High
EPSS probability0.23%
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 Concrete CMS before 9.5.3 allows remote authenticated users to execute script in dashboard users' sessions. The country-less Address text formatter skips HTML escaping, and Express association templates echo the resulting label mask without applying h(). Exploitation requires permission to submit an Address attribute with a blank country and a dashboard user to open the affected entry, placing that user's session actions and data at risk.

The record

CVE
CVE-2026-81898
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Concrete CMS
Product
Concrete CMS
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=5.0.0 <=9.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Concrete CMS · Concrete CMSversion=5.0.0 <=9.5.2

Published CVSS scores

7.5Concrete CMS Security TeamCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

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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