CVE-2026-7887Network attack vector

API token issuance via ignored account status

Published May 21, 2026 · Updated May 21, 2026

Authentication bypass in Concrete CMS 9.5.0 and earlier allows remote authenticated users to obtain API tokens through OAuth 2.0. The authorization-code handler issues tokens without checking the matched account’s uIsActive flag, so a value of 0 is ignored. Exploitation requires a disabled account that can complete the configured OAuth flow; granted token scopes bound the accessible API data and actions.

CVSS severity2.3
Low
EPSS probability0.17%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Concrete CMS 9.5.0 and earlier allows remote authenticated users to obtain API tokens through OAuth 2.0. The authorization-code handler issues tokens without checking the matched account’s uIsActive flag, so a value of 0 is ignored. Exploitation requires a disabled account that can complete the configured OAuth flow; granted token scopes bound the accessible API data and actions.

The record

CVE
CVE-2026-7887
Published
May 21, 2026
Updated
May 21, 2026
Vendor
Concrete CMS
Product
Concrete CMS
Classifications
CWE-1287, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 21, 2026CVE publishedPublication date reported by the CVE source.
  2. May 21, 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=5.0 <=9.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Concrete CMS · Concrete CMSversion=5.0 <=9.5.0

Published CVSS scores

2.3ConcreteCMSCVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
6.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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

CWE-1287Improper Validation of Specified Type of Input
T1190Exploit Public-Facing Application

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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