EUVD-2025-201457Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A07:2021 - Identification and Authentication Failures
ASVS 5.0
V2 - Authentication Authentication mechanism strength, credential management
MITRE ATT&CK
2 techniques across 2 tactics: Defense Evasion, Initial Access The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | Unauthorized access to protected functionality, data, or administrative interfaces, potentially leading to full system compromise. With a CVSS score of 2.7 (LOW), this represents a low risk. |
| Exploit ScenarioDerived | An attacker manipulates authentication tokens, exploits logic flaws, or uses default credentials to bypass the login mechanism and access restricted areas. |
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Alert meAnalysisAIv1 – Mar 15, 2026
The Nextcloud Approval app allows approval or disapproval of files in the sidebar. Prior to 1.3.1 and 2.5.0, an authenticated user listed as a requester in a workflow can set another user’s file into the “pending approval” without access to the file by using the numeric file id. This vulnerability is fixed in 1.3.1 and 2.5.0.
Earlier versions of this analysis (1)
RemediationAI
A vendor patch is available — apply it immediately. Implement robust authentication mechanisms. Use multi-factor authentication. Review authentication logic for bypass conditions. Remove default credentials.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in euvd
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
An authentication bypass vulnerability allows attackers to circumvent login mechanisms and gain unauthorized access without valid credentials. This vulnerability is classified as Improper Authentication (CWE-287).
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Severity by source
AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
Primary rating from Vendor (github) · only source for this CVE.
CVSS VectorVendor: github
Lifecycle Timeline
2Executive ViewAI
CVE-2025-66515 is a low-severity vulnerability in the sidebar. involving authentication failure (CVSS 2.7). The limited severity suggests constrained impact, typically requiring specific conditions or local access for exploitation. A patch is available and can be applied during standard maintenance windows.
Apply vendor patch during routine maintenance. Standard security controls provide adequate interim protection.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Authentication bypass attacks exploit flaws in the verification mechanisms that control access to systems and applications.
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