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Fencer Vulns
high 7.4

CVE-2026-18115 json

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

published 2026-09-15 54 d ago modified 2026-09-16 53 d ago also EUVD-2026-78913

cvss
7.4
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

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.

Patch / fix

  • concretecms concrete_cms 9.5.3

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
54 d ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.4 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
CNA 4.0 7.4 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • Concrete CMS Concrete CMS

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.