Vulnerability Details CVE-2026-55761
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.003
EPSS Ranking 19.1%
CVSS Severity
CVSS v3 Score 5.9
References
- https://github.com/portainer/portainer/commit/49f19107cf9a3540cbe406c9eb7f24390e1af02b
- https://github.com/portainer/portainer/commit/d2b56efcb4e43c4168bb6688eee9f6bf22867312
- https://github.com/portainer/portainer/issues/2770
- https://github.com/portainer/portainer/releases/tag/2.39.4
- https://github.com/portainer/portainer/releases/tag/2.43.0
- https://github.com/portainer/portainer/security/advisories/GHSA-x626-fcwx-f5pc
Products affected by CVE-2026-55761
-
cpe:2.3:a:portainer:portainer:2.39.0
-
cpe:2.3:a:portainer:portainer:2.39.1
-
cpe:2.3:a:portainer:portainer:2.39.2
-
cpe:2.3:a:portainer:portainer:2.39.3
-
cpe:2.3:a:portainer:portainer:2.40.0
-
cpe:2.3:a:portainer:portainer:2.41.0
-
cpe:2.3:a:portainer:portainer:2.41.1
-
cpe:2.3:a:portainer:portainer:2.42.0