Vulnerability Description
Portainer Community Edition is a lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, Kubernetes and ACI environments. In versions 2.39.0 through 2.39.3 and 2.40.0 until 2.43.0, unauthenticated restore and administrator initialization endpoints (/api/restore and /api/users/admin/init) remain accessible during the five-minute setup window for uninitialized instances, allowing a network attacker to restore a crafted backup or create the first administrator account and gain full administrative access. This issue is fixed in versions 2.39.4 and 2.43.0.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Portainer | Portainer | >= 2.39.0, < 2.39.4 |
Related Weaknesses (CWE)
References
- https://github.com/portainer/portainer/commit/49f19107cf9a3540cbe406c9eb7f24390ePatch
- https://github.com/portainer/portainer/commit/d2b56efcb4e43c4168bb6688eee9f6bf22Patch
- https://github.com/portainer/portainer/issues/2770Issue Tracking
- https://github.com/portainer/portainer/releases/tag/2.39.4Release Notes
- https://github.com/portainer/portainer/releases/tag/2.43.0Release Notes
- https://github.com/portainer/portainer/security/advisories/GHSA-x626-fcwx-f5pcExploitMitigationVendor Advisory
FAQ
What is CVE-2026-55761?
CVE-2026-55761 is a vulnerability with a CVSS score of 5.9 (MEDIUM). Portainer Community Edition is a lightweight service delivery platform for containerized applications that can be used to manage Docker, Swarm, Kubernetes and ACI environments. In versions 2.39.0 thro...
How severe is CVE-2026-55761?
CVE-2026-55761 has been rated MEDIUM with a CVSS base score of 5.9/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55761?
Check the references section above for vendor advisories and patch information. Affected products include: Portainer Portainer.