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CVE-2026-55641· NVD / CVE Program· CNA GitHub_M

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

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.32% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: decolua 9router 0.5.2.

Low priority for now. Upgrade to decolua 9router 0.5.2 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 8.2 · v3.1—No exploit Fix available
Published
Jul 10, 2026
Updated
Jul 10, 2026
EPSS
0.3% · 23th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
8.2
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • decolua 9router

    • < 0.5.2affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
npm9routerbefore 0.5.20.5.2

Same product

decolua: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-463399Router: Unauthenticated Remote Code Execution via unprotected MCP custom plugin routes
    41Plan
  • CVE-2026-493529Router: Hardcoded Default fallback JWT Secret Allows Authentication Bypass
    39Monitor
  • CVE-2026-555009router: Exposure of Sensitive Information and Unprotected Database Import/Export Allows Complete Credential Theft and Database Takeover
    39Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-56676Jul 10, 2026 · 9router: Image prefetch DNS rebinding allows SSRF to internal services
    29Monitor
  • ← EarlierCVE-2026-55638Jul 10, 2026 · 9router: Unauthenticated LLM proxy access via /codex rewrite authorization bypass
    34Monitor
  • Later →CVE-2026-56675Jul 10, 2026 · 9router: Reverse proxy locality collapse allows unauthenticated access to 9router /v1 APIs
    33Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
decolua 9router0.5.2 · descriptionVendor (CNA)
npm:9router0.5.2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-493535 days apart9Router: Local-Only Access Gate Bypass in 9router via Host Header SpoofING
    30Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-623125 days apart9Router: Authenticated RCE via Unvalidated MCP Plugin Arguments
    35Monitor
  • CVE-2026-6331313 days apart9Router before 0.4.72 Server-Side Request Forgery via /v1/web/fetch
    33Monitor
  • CVE-2026-566760 days apart9router: Image prefetch DNS rebinding allows SSRF to internal services
    29Monitor
  • CVE-2026-566785 days apart9Router: Kiro region injection allows authenticated SSRF with Authorization header forwarding
    25Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-290 · Authentication Bypass by Spoofing

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records