Internal service discovery via issuerUrl SSRF
Published Aug 17, 2026 · Updated Aug 18, 2026
Server-side request forgery in Decolua 9Router 0.5.4 and earlier allows remote attackers to scan internal services via issuerUrl. The POST /api/auth/oidc/test handler passes the user-supplied issuerUrl to fetchOidcDiscovery(), which requests /.well-known/openid-configuration without blocking loopback or private-network destinations and then reflects parsed fields such as token_endpoint and jwks_uri. Reachability depends on dashboard login being disabled; under that condition, no session is required and successful probes can confirm internal HTTP services or disclose returned OIDC metadata.
Summary
What happened
Server-side request forgery in Decolua 9Router 0.5.4 and earlier allows remote attackers to scan internal services via issuerUrl. The POST /api/auth/oidc/test handler passes the user-supplied issuerUrl to fetchOidcDiscovery(), which requests /.well-known/openid-configuration without blocking loopback or private-network destinations and then reflects parsed fields such as token_endpoint and jwks_uri. Reachability depends on dashboard login being disabled; under that condition, no session is required and successful probes can confirm internal HTTP services or disclose returned OIDC metadata.
The record
- CVE
- CVE-2026-56677
- Published
- Aug 17, 2026
- Updated
- Aug 18, 2026
- Vendor
- Decolua
- Product
- 9Router
- Classifications
- CWE-918, CWE-306, T1046, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 17, 2026CVE publishedPublication date reported by the CVE source.
- Aug 18, 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.
- Affected versionversion=<= 0.5.4
What conditions does exploitation require?
What is affected?
Published CVSS scores
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.
Weakness, pattern, technique
Public exploit references
- GHSA-8g4w-4ffg-8vgx proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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