CVE-2026-55641

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.

CVSS 3.1

8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N

EPSS

0.3% chance of exploitation in the next 30 days; higher than 25% of CVEs (scores of 2026-10-25)

CWEs

CWE-290, CWE-348, CWE-918, CWE-1327

Published

2026-07-10

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Packages (OSV)

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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