CVE-2026-85385
Undergoing Analysis Undergoing Analysis - In Progress

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Vulnerability report for CVE-2026-85385, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-16

Last updated on: 2026-09-17

Assigner: ConcreteCMS

Description

Concrete CMS below 9.5.4 did not validate the user timezone value (uTimezone) on write and rendered it without output encoding on the Dashboard user management page, where Date::getTimezoneDisplayName() returns any non-IANA value unchanged. A stored cross-site scripting payload saved in this field executed in an administrator's browser when they viewed the affected user in the Dashboard, running script in the admin session (for example to read CSRF tokens, create administrator accounts, or change site settings). In Concrete CMS 9.5.3 the field became reachable by unauthenticated visitors through public registration; in Concrete CMS below 9.5.3, the same field was reachable by any authenticated user through the account profile editor. Exploitation required concrete.misc.user_timezones to be enabled (off by default), and the unauthenticated path additionally required public registration to be enabled. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.7 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N. Thanks Suraj Bhosale for reporting.

CVSS Scores

EPSS Scores

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Meta Information

Published
2026-09-16
Last Modified
2026-09-17
Generated
2026-09-20
EPSS Evaluated
N/A
NVD

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
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.

Attack-Flow Graph

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