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Vulnerability · Published Jul 8, 2026 · Assigned by GitHub_M

CVE-2026-55761Portainer: Unauthenticated Restore Endpoint Allows Admin Takeover on Uninitialised Portainer Instances

High 7.1

In plain English

A high-severity improper authentication in portainer from portainer. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 43% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)7.1High
Exploit odds (30 days)0.5%top 57.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/portainer/portainer2.39.4GHSA-x626-fcwx-f5pc
Gogithub.com/portainer/portainer2.43.0GHSA-x626-fcwx-f5pc
Gogithub.com/portainer/portainerno fix listedGO-2026-6324

Affected products (as reported)

VendorProductVersions
portainer portainer >= 2.39.0, < 2.39.4

Weakness: CWE-287 · Vector: 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

References