CVE-2026-81926Network attack vectorHinoki check available

Stored XSS via unescaped duplicate page paths

Published Sep 15, 2026 · Updated Sep 15, 2026

Stored XSS in Concrete CMS 9.4.0 through 9.5.2 allows remote authenticated users to execute script through a crafted colliding page path. The location-panel check endpoint returns the submitted path unchanged in JSON, and client code inserts it into the duplicate-path dialog as raw HTML. Exploitation requires page-editing privileges and a collision that causes the authenticated editor's browser to render the confirmation dialog.

CVSS severity2.0
Low
EPSS probability0.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Stored XSS in Concrete CMS 9.4.0 through 9.5.2 allows remote authenticated users to execute script through a crafted colliding page path. The location-panel check endpoint returns the submitted path unchanged in JSON, and client code inserts it into the duplicate-path dialog as raw HTML. Exploitation requires page-editing privileges and a collision that causes the authenticated editor's browser to render the confirmation dialog.

The record

CVE
CVE-2026-81926
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Concrete CMS
Product
Concrete CMS
Classifications
T1203
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=9.4.0 <=9.5.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Concrete CMS · Concrete CMSversion=9.4.0 <=9.5.2

Published CVSS scores

2.0Concrete CMSCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:L/VI:L/VA:L/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.

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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

T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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