CVE-2026-56677: CWE-306: Missing Authentication for Critical Function in decolua 9router
CVE-2026-56677 is a high-severity vulnerability in decolua 9router version 0.5.4 and earlier. It involves a missing authentication check on the POST /api/auth/oidc/test endpoint, which allows unauthenticated attackers to supply a user-controlled issuerUrl parameter. This parameter is passed to a function that fetches OIDC discovery data without restricting access to private or loopback network destinations. As a result, attackers can scan internal services and obtain sensitive OpenID Connect discovery information such as token_endpoint and jwks_uri, even when dashboard login is disabled.
AI Analysis
Technical Summary
The vulnerability in decolua 9router (<=0.5.4) occurs because the POST /api/auth/oidc/test endpoint accepts an issuerUrl parameter from unauthenticated users and passes it to fetchOidcDiscovery() without validating or restricting network destinations. This allows attackers to perform internal network scanning and retrieve OIDC discovery fields including token_endpoint and jwks_uri. The flaw is classified under CWE-306 (Missing Authentication for Critical Function) and CWE-918 (Server-Side Request Forgery). The CVSS 3.1 score is 8.6, indicating high severity with network attack vector, low attack complexity, no privileges or user interaction required, and impacts confidentiality, integrity, and availability.
Potential Impact
An unauthenticated attacker can exploit this vulnerability to scan internal network services and retrieve sensitive OpenID Connect discovery information such as token endpoints and JSON Web Key Set URIs. This information disclosure can aid further attacks on internal services. The vulnerability affects confidentiality and integrity, with limited impact on availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the affected endpoint and monitor for unusual requests targeting the /api/auth/oidc/test endpoint. Consider disabling or restricting the issuerUrl parameter usage if possible.
CVE-2026-56677: CWE-306: Missing Authentication for Critical Function in decolua 9router
Description
CVE-2026-56677 is a high-severity vulnerability in decolua 9router version 0.5.4 and earlier. It involves a missing authentication check on the POST /api/auth/oidc/test endpoint, which allows unauthenticated attackers to supply a user-controlled issuerUrl parameter. This parameter is passed to a function that fetches OIDC discovery data without restricting access to private or loopback network destinations. As a result, attackers can scan internal services and obtain sensitive OpenID Connect discovery information such as token_endpoint and jwks_uri, even when dashboard login is disabled.
CVSS v3.1
Score 8.6high
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in decolua 9router (<=0.5.4) occurs because the POST /api/auth/oidc/test endpoint accepts an issuerUrl parameter from unauthenticated users and passes it to fetchOidcDiscovery() without validating or restricting network destinations. This allows attackers to perform internal network scanning and retrieve OIDC discovery fields including token_endpoint and jwks_uri. The flaw is classified under CWE-306 (Missing Authentication for Critical Function) and CWE-918 (Server-Side Request Forgery). The CVSS 3.1 score is 8.6, indicating high severity with network attack vector, low attack complexity, no privileges or user interaction required, and impacts confidentiality, integrity, and availability.
Potential Impact
An unauthenticated attacker can exploit this vulnerability to scan internal network services and retrieve sensitive OpenID Connect discovery information such as token endpoints and JSON Web Key Set URIs. This information disclosure can aid further attacks on internal services. The vulnerability affects confidentiality and integrity, with limited impact on availability.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the affected endpoint and monitor for unusual requests targeting the /api/auth/oidc/test endpoint. Consider disabling or restricting the issuerUrl parameter usage if possible.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-22T16:39:01.044Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a837c93bf8831d53998337d
Added to database: 08/17/2026, 21:26:43 UTC
Last enriched: 08/17/2026, 21:41:08 UTC
Last updated: 08/17/2026, 21:41:08 UTC
Views: 4
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