CVE-2026-55761
Portainer: Unauthenticated Restore Endpoint Allows Admin Takeover on Uninitialised Portainer Instances
- State
- Published
- Severity
- 7.1 High
- Published
- Jul 8, 2026
- Updated
- Jul 8, 2026
- Reserved
- Jun 17, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 7.1 High | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:H/SI:H/SA:H | GitHub_M |
Weaknesses
- CWE-287 Improper Authentication
Affected Products
| Product | Versions |
|---|---|
portainerportainer |
|
References
- https://github.com/portainer/portainer/security/advisories/GHSA-x626-fcwx-f5pc
- https://github.com/portainer/portainer/issues/2770
- https://github.com/portainer/portainer/commit/49f19107cf9a3540cbe406c9eb7f24390e1af02b
- https://github.com/portainer/portainer/commit/d2b56efcb4e43c4168bb6688eee9f6bf22867312
- https://github.com/portainer/portainer/releases/tag/2.39.4
- https://github.com/portainer/portainer/releases/tag/2.43.0
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.