Concrete CMS EUVD-2026-31364

Q: What is the CVSS score of EUVD-2026-31364?

EUVD-2026-31364 has a CVSS 4.0 base score of 2.3 (Low). CVSS 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/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. EPSS exploitation probability: 0.1%.

| CVE-2026-7887 LOW

Improper Validation of Specified Type of Input (CWE-1287)

2026-05-21 ConcreteCMS

GHSA-f54h-78c9-c24h

Authentication Bypass Concrete Cms

2.3

CVSS 4.0

CVSS VectorNVD

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/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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

May 21, 2026 - 22:35 vuln.today

DescriptionNVD

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.

AnalysisAI

OAuth 2.0 Authorization Code handler in Concrete CMS 9.5.0 and earlier fails to enforce account status checks, allowing users with suspended, banned, or terminated accounts (uIsActive=0) to complete OAuth flows and receive valid API tokens. Deployments using OAuth 2.0 as an authentication mechanism are affected, with the primary real-world impact being unauthorized continued access by deprovisioned users - such as terminated employees or revoked contractors - who retain OAuth credentials. …

Analysis

Detailed AI-generated intelligence summary covering attack vector, impact assessment, affected versions, remediation steps, and indicators of compromise.

POChttps://••••••••••.com/exploit

PATCHhttps://••••••••••.com/patch

ADVISORYhttps://••••••••••.com/advisory

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EUVD-2026-31364 vulnerability details – vuln.today

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