What it is
CVE-2026-59800 is an unauthenticated vulnerability affecting decolua 9router. 9Router before 0.4.44 contains an OS command injection vulnerability in the unauthenticated POST /api/tunnel/tailscale-install endpoint...
Vulnerability report
Active exploitation observed
Confirmed confidence
Not in CISA KEV
CVE-2026-59800
9router < 0.4.44 OS Command Injection
decolua / 9router · affected before 0.4.44
- Severity
- CVSS 9.2 · Critical
- Confidence
- Confirmed
- Exploit status
- Observed in sensors
- EPSS
- 1.3%
- First observed
- 10 Jul 2026
- Last observed
- 14 Jul 2026
Decision summary
What security teams need to know first
Direct answers before the deeper technical record.
Is it exploited?
Yes. KEV Intelligence sensors observed exploitation attempts with confirmed confidence.
Who is affected?
decolua / 9router affected before 0.4.44.
What should we do?
Patch immediately, validate internet-facing exposure, and monitor for matching requests.
Overview
9router < 0.4.44 OS Command Injection
9Router before 0.4.44 contains an OS command injection vulnerability in the unauthenticated POST /api/tunnel/tailscale-install endpoint (this route is not covered by the dashboard middleware matcher, so no authorization check is applied). The sudoPassword field from the request body is written to the stdin of a 'sudo -S sh' child process.
When sudo does not prompt for a password (the process runs as root, NOPASSWD is configured, or a recent sudo timestamp cache exists), the sudoPassword value is interpreted by sh as a shell command, allowing a remote unauthenticated attacker to execute arbitrary OS commands. Exploitation evidence was first observed by the Shadowserver Foundation on 2026-07-04 (UTC).
Vendor
Product
Affected
Status
decolua
9router
Before 0.4.44
Affected
decolua
9router
0.4.44
Unaffected
- Published
- 07 Jul 2026
- Exploited Since
- 10 Jul 2026
- Attack vector
- Remote
- Complexity
- Low
- Privileges
- None
- User interaction
- None
Tags
edge
CVE References
- CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2026-59800
- GitHub Security Advisory (GHSA-g6g7-pvmx-m74p) github.com · Vendor Advisory https://github.com/decolua/9router/security/advisories/GHSA-g6g7-pvmx...
- Third-Party Advisory — vulncheck.com vulncheck.com · Third-Party Advisory https://www.vulncheck.com/advisories/9router-os-command-injection-via...
Exploitation evidence
Why KEV Intelligence marks this CVE as exploited
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
Exploited in the wild
The Shadowserver
Independent exploitation attestation added to the KEV Intelligence record.
Active exploitation observed
KEV Intelligence sensor
First-party sensor telemetry confirms matching exploitation attempts.
Proof of concept available
Pruva
Public scanner or PoC coverage increases practical exploitability.
Known exploited vulnerability sources
Per-source evidence links for KEV attestations are available through the KEV Intelligence Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2026-07-31 00:00 UTC |
| KEV Intelligence | 2026-08-01 11:09 UTC |
Operational indicators for this CVE are listed under Detection.
Sensor telemetry
First-party evidence of exploitation activity
Aggregate observations show the scale, recency, and distribution of activity without overstating sparse data.
0
Attempts observed
0
Unique attacker IPs
—
Attacker countries
—
Sensors observed
Exploitation attempts over the last 42 days
Daily events observed by KEV Intelligence sensors
Updated 19 Aug 2026
9 Jul
18 Jul
27 Jul
5 Aug
19 Aug
First observed 10 Jul 2026 · Last observed 14 Jul 2026
Pro adds sensor region and window summaries. Enterprise adds raw IPs, paths, User-Agents, and payloads.
Detection
Operational artifacts and observed signals
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Observed signals
- Request targets
- 0
- User-Agents
- 0
Raw values available in Pro and Enterprise.
Scanner coverage
No scanner integrations recorded yet.
Virtual patch status
No KEV Intelligence virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Attacker IP Indicators
Attacker IP indicators observed · available in Pro and Enterprise.
Sensor-derived attacker IP indicators are available to Pro and Enterprise accounts under Detection and through the Pro API.
Learn about Pro API accessRisk and context
Severity, weaknesses, and research context
CVSS v4.0
9.2
Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS
1.3%
All CVSS Scores
CVSS v4.0
9.2
Critical
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS v3.1
9.8
Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
9router before 0.4.44 allows unauthenticated remote OS command execution via the /api/tunnel/tailscale-install endpoint by injecting shell commands in the sudoPassword field when sudo does not prompt for a password.
pruva · Created 2026-07-08 04:50:47 UTC
Severity: CRITICAL | CVE: CVE-2026-59800 | Package: 9router (npm)
Timeline
From disclosure to observed exploitation
-
Added to KEV Intelligence KEV Feed
High-confidence, third-party attested exploitation
-
Observed by KEV Intelligence sensors
Evidence-backed exploitation signal
-
Indicators of compromise added (3)
Indicators of compromise recorded
-
Public PoC available
Public proof-of-concept code published
-
CVE published
Vulnerability disclosed publicly
-
CVE ID reserved
Identifier reserved by the CNA
Pro API
Automate this intelligence
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
- Evidence confidence and provenance
- First-party sensor telemetry
- PoC and scanner references
- Affected versions and enrichment
- Automation-ready JSON delivery
GET /api/v2/pro/kevs/CVE-2026-59800
Free JSON includes basic KEV fields{
"cve_id": "CVE-2026-59800",
"confidence": "Confirmed",
"cvss_score": 9.2,
"cvss_estimated": false,
"epss_score": 0.01338,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}Early warning alerts
Get alerts on high-impact exploitation
Receive curator-selected alerts when exploitation activity warrants attention. Each alert includes the evidence and context needed to decide what requires attention now.