In Concrete CMS 9.2.0 to 9.5.2, Missing Authorization in REST API Users update() and change_password Enables Account Takeover. (CVE-2026-18115) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-18115

In Concrete CMS 9.2.0 to 9.5.2, Missing Authorization in REST API Users update() and change_password Enables Account Takeover.

Answer in brief

CVE-2026-18115 records a Unknown severity vulnerability in In Concrete CMS 9.2.0 to 9.5.2, Missing Authorization in REST API Users update() and change_password Enables Account Takeover.. The current sources do not mark it as known exploited. The current feed maps Concrete CMS/Concrete CMS (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 15, 2026Updated Sep 15, 2026Source checked Sep 16, 2026First seen by HOL Sep 15, 2026Material review Sep 15, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Concrete CMS/Concrete CMS (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Concrete CMS/Concrete CMSgeneric	9.2.0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Concrete CMS/Concrete CMS.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 15, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 15, 2026

Sources and claim methodology

Source referencedocumentation.concretecms.org

Upstream source description

Concrete CMS 9.2.0 to 9.5.2 did not enforce per-field edit_user_properties permissions on the REST API user write endpoints (PUT /ccm/api/1.0/users/{uID} and POST /ccm/api/1.0/users/{uID}/change_password). A user with an update-scoped OAuth token and permission to edit only one non-sensitive field could change another non-superuser's password, username, email, and attributes, taking over that account. The Concrete CMS security team gave this vulnerability a CVSS v4.0 score of 7.4 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N. Thanks riodrwn for reporting.

Quoted source text, attributed separately from HOL analysis.