CVE-2026-56679: 9Router: Mass assignment in PATCH /api/settings allows authenticated authorization downgrade

Severity: high (CVSS 8.7 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-15 · updated 2026-10-24
Weakness: CWE-915

Description

9Router is an AI router & token saver. Prior to 0.5.4, the PATCH /api/settings endpoint writes the entire request body to persistent settings without a field whitelist, allowing an authenticated user to set security-critical fields such as requireLogin and disable authentication for the whole application, exposing protected routes such as /api/keys and /api/providers to unauthenticated access. This issue is reported as fixed in version 0.5.4.

Affected products

decolua 9router: before 0.5.4

References

https://github.com/decolua/9router/security/advisories/GHSA-vmjq-hvgq-2wv4
https://github.com/decolua/9router/security/advisories/GHSA-vmjq-hvgq-2wv4

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