Concrete CMS up to 9.5.2 Waiting For Me Block cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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3.5$0-$5k0.00-

Summaryinfo

A vulnerability classified as problematic was found in Concrete CMS up to 9.5.2. The impacted element is an unknown function of the component Waiting For Me Block. The manipulation results in cross site scripting. This vulnerability is reported as CVE-2026-18116. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Concrete CMS up to 9.5.2. It has been classified as problematic. Affected is an unknown function of the component Waiting For Me Block. The manipulation with an unknown input leads to a cross site scripting vulnerability. CWE is classifying the issue as CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. This is going to have an impact on integrity. CVE summarizes:

Concrete CMS 8.3.0 to 9.5.2 stored calendar event names without sanitization and rendered them without HTML escaping in the workflow approval and deletion notifications shown in the dashboard "Waiting For Me" block. A registered user permitted to add events to a calendar governed by an approval workflow could submit an event whose name contained a script payload, which then executed in an administrator's browser when the pending request was displayed and could be used to create a new administrator account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks v01demort for reporting.

The advisory is shared for download at documentation.concretecms.org. This vulnerability is traded as CVE-2026-18116 since 07/28/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.5

VulDB Base Score: 3.5
VulDB Temp Score: 3.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Cross site scripting
CWE: CWE-79 / CWE-94 / CWE-74
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

07/28/2026 CVE reserved
09/14/2026 +48 days VulDB entry created
09/15/2026 +0 days Advisory disclosed
09/15/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: documentation.concretecms.org
Status: Not defined

CVE: CVE-2026-18116 (🔒)
GCVE (CVE): GCVE-0-2026-18116
GCVE (VulDB): GCVE-100-403872

Entryinfo

Created: 09/15/2026 00:39
Changes: 09/15/2026 00:39 (64)
Complete: 🔍
Cache ID: 216::103

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