What it is
CVE-2026-40242 is an unauthenticated vulnerability affecting Getarcaneapp arcane. Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 1.17.3, the /api/templates/fetch...
Vulnerability report
arcane Server-Side Request Forgery
Getarcaneapp / arcane · affected before 1.17.3
Decision summary
Direct answers before the deeper technical record.
What it is
CVE-2026-40242 is an unauthenticated vulnerability affecting Getarcaneapp arcane. Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 1.17.3, the /api/templates/fetch...
Is it exploited?
Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is high. Also confirmed by third-party sources.
Who is affected?
Getarcaneapp / arcane affected before 1.17.3.
What should we do?
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
Overview
Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to 1.17.3, the /api/templates/fetch endpoint accepts a caller-supplied url parameter and performs a server-side HTTP GET request to that URL without authentication and without URL scheme or host validation. The server's response is returned directly to the caller.
type. This constitutes an unauthenticated SSRF vulnerability affecting any publicly reachable Arcane instance. This vulnerability is fixed in 1.17.3.
Exploitation evidence
Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.
The Shadowserver
A trusted third party reported exploitation.
Nuclei Templates
Public scanner or PoC coverage increases practical exploitability.
Per-source evidence links for KEV attestations are available through the Previdian Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2026-09-17 00:00 UTC |
Detection
Make the evidence actionable in scanner, SOC, and edge-control workflows.
Request targets and User-Agents available in Pro. Callback host details available in Enterprise.
Nuclei template detected 01 Jun 2026.
View Nuclei template (opens in new tab)No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.
Learn about virtual patches →Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-40242.yaml | 01 Jun 2026 |
Risk and context
CVSS v3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS
0.6%
These PoCs are unverified and could contain malware. Use at your own risk.
nuclei · Created Unknown
Timeline
00:00 UTC
High-confidence, third-party attested exploitation
14:21 UTC
Public proof-of-concept code published
15:34 UTC
Scanner coverage available
20:34 UTC
Vulnerability disclosed publicly
17:31 UTC
Identifier reserved by the CNA
Pro API
Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
GET /api/v2/pro/kevs/CVE-2026-40242
Free JSON includes basic KEV fields{
"cve_id": "CVE-2026-40242",
"confidence": "High",
"cvss_score": 7.2,
"cvss_estimated": false,
"epss_score": 0.00621,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "attempts": 0, "sensors": 0 }
}