CVE-2026-556419router: Unauthenticated `/v1` proxy access via `Host`-header spoofing → open AI relay + SSRF
- 8.2HighCVSS base score
- 0.33%Exploitation in 30 daysEPSS · top 74% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 24 days later
· 24 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
| NVDNVD · Deferred | 3.1 | High8.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
- EPSS (exploitation in 30 days)
- 0.33% · top 74% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.2.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- npm9routerGHSA-86m2-fcxq-5q7c (opens in a new tab)
References
References3
- https://github.com/decolua/9router/security/advisories/GHSA-86m2-fcxq-5q7c (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/decolua/9router/commit/b282f0554972ea35281520738759d76abcd0b0b3 (opens in a new tab)x_refsource_MISC
- https://github.com/decolua/9router/releases/tag/v0.5.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-42930 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-86m2-fcxq-5q7c (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-55641)Record last updated .