Concrete CMS up to 9.5.0 OAuth 2.0 Authorization improper validation of specified type of input

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Concrete CMS up to 9.5.0. This vulnerability affects unknown code of the component OAuth 2.0 Authorization. Executing a manipulation can lead to improper validation of specified type of input. The identification of this vulnerability is CVE-2026-7887. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical was found in Concrete CMS up to 9.5.0. This vulnerability affects an unknown code block of the component OAuth 2.0 Authorization. The manipulation with an unknown input leads to a improper validation of specified type of input vulnerability. The CWE definition for the vulnerability is CWE-1287. The product receives input that is expected to be of a certain type, but it does not validate or incorrectly validates that the input is actually of the expected type. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

For Concrete CMS 9.5.0 and below, OAuth 2.0 Authorization-Code Handler Bypasses Account Status. A user with uIsActive=0 (suspended, banned, terminated employee) can still authenticate via OAuth and receive valid API tokens. The Concrete CMS security team gave this vulnerability a CVSS v.4.0 score of 2.3 with vector CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N. Thanks 0x4c616e for reporting.

The weakness was shared by 0x4c616e. The advisory is shared for download at documentation.concretecms.org. This vulnerability was named CVE-2026-7887 since 05/05/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/22/2026).

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

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

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: 6.3
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.3
VulDB Temp Score: 6.3
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: Improper validation of specified type of input
CWE: CWE-1287 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

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

05/05/2026 CVE reserved
05/22/2026 +17 days Advisory disclosed
05/22/2026 +0 days VulDB entry created
05/22/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: documentation.concretecms.org
Researcher: 0x4c616e
Status: Not defined

CVE: CVE-2026-7887 (🔒)
GCVE (CVE): GCVE-0-2026-7887
GCVE (VulDB): GCVE-100-365104

Entryinfo

Created: 05/22/2026 06:03
Changes: 05/22/2026 06:03 (66)
Complete: 🔍
Cache ID: 216::103

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