What’s Vulnerable › Vulnerabilities

CVE-2026-55641: 9router: Unauthenticated `/v1` proxy access via `Host`-header spoofing → open AI relay + SSRF

• Severity: high (CVSS 8.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-10 · updated 2026-10-25
• Weakness: CWE-290

Description

9Router is an AI router & token saver. Prior to 0.5.2, 9router determines whether a /v1 LLM proxy request is local by reading the client-controlled Host header, allowing a remote unauthenticated attacker to send Host: localhost and bypass API-key authentication. In the default configuration, this exposes the /v1 proxy to upstream provider calls using stored provider credentials and allows /v1/search with the searxng provider_options.baseUrl parameter to drive server-side requests to internal or cloud-metadata hosts. This issue is fixed in version 0.5.2.

Affected products

• decolua 9router: before 0.5.2

References

• https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3
• https://github.com/decolua/9router/releases/tag/v0.5.2
• https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c
• https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c

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