CVE-2026-42461
HighArcane Vulnerable to Unauthenticated Disclosure of Custom Compose Template Content (incl.
Published Apr 30, 2026 · Updated Aug 12, 2026 · Also known as GHSA-cxx3-hr75-4q96, GO-2026-5340
Key Facts
Patch in the next maintenance window- CVE-2026-42461 is a high-severity vulnerability (CVSS 8.7 v4) affecting Arcane (Getarcane), github.com/getarcaneapp/arcane/backend (go).
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 1.5% probability of exploitation in the next 30 days.
- Fixed versions are available, including Arcane 1.18.0, github.com/getarcaneapp/arcane/backend 1.18.0.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
CVSS v4
8.7
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS (30-day exploit likelihood)
1.5%
Higher than 73.3% of all scored CVEs
Exploited in the wild
No known
Not in a known-exploited catalog
Public exploit code
None known
Get the full CVE-2026-42461 brief as a PDF
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Description
Arcane is an interface for managing Docker containers, images, networks, and volumes. Prior to version 1.18.0, four GET endpoints under /api/templates* in Arcane's Huma backend are registered without any Security requirement, allowing any unauthenticated network client to list and read the full Compose YAML and .env content of every custom template stored in the instance. Because Arcane's UI exposes a "Save as Template" flow on the project / swarm-stack creation pages that persists the operator's real env content (database passwords, API keys, etc.) verbatim, this missing authorization is an unauthenticated read of operator secrets in practice — not a theoretical info-disclosure. The frontend explicitly treats /customize/templates/* as an authenticated area (PROTECTED_PREFIXES in frontend/src/lib/utils/redirect.util.ts), and every CRUD operation (POST/PUT/DELETE) on the same paths requires a Bearer/API key, so this is a clear backend authorization gap, not intended public access. This issue has been patched in version 1.18.0.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| ArcaneGetarcane | >= < 1.18.0 | 1.18.0 |
| github.com/getarcaneapp/arcane/backendgo | See advisory | 1.18.0 |
Patched Releases
Arcane
1.18.0
github.com/getarcaneapp/arcane/backend
1.18.0
Timeline
Publicly disclosed
Apr 30, 2026
Last updated
Aug 12, 2026
Weakness Type
- CWE-862 Missing Authorization
References
- advisoryGHSA advisory
- advisoryhttps://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42461.json
- advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-42461
- articlehttps://github.com/getarcaneapp/arcane/releases/tag/v1.18.0
- articlehttps://github.com/getarcaneapp/arcane/security/advisories/GHSA-cxx3-hr75-4q96
FAQ
Common Questions.
Arcane is an interface for managing Docker containers, images, networks, and volumes.
Affected: Arcane (Getarcane) versions >= < 1.18.0; github.com/getarcaneapp/arcane/backend (go). The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Arcane 1.18.0, github.com/getarcaneapp/arcane/backend 1.18.0.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
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