CVE-2026-55761: Portainer Community Edition is a lightweight service delivery platform for containerized applications that can

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MEDIUM 5.9REMOTEUPGRADE

CVE-2026-55761 is a medium-severity flaw (CVSS 5.9) affecting portainer. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 atta

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.5% (top 58%)
CISA exploited list	No
Weakness	CWE-287
Published	2026-07-08
Last modified	2026-07-10

Publisher (CNA): GitHub, Inc. · Vendor: portainer

Last updated 2026-07-10 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-08 16:16 UTCPublished CVE record published
2026-07-10 17:48 UTCUpdated Record last modified

portainer portainer UPGRADE

Affected: >= 2.39.0 and < 2.39.4 · >= 2.40.0 and < 2.43.0

Fixed in: 2.39.4, 2.43.0

Safe to downgrade to: a release before 2.39.0

1. Check installed version

apt-cache policy portainer || rpm -q portainer || portainer --version

2. UPGRADE to 2.39.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade portainer

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade portainer

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 2.39.0 (Debian / Ubuntu)

apt-cache madison portainer sudo apt install portainer=<VERSION_BEFORE_2.39.0> sudo apt-mark hold portainer

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list portainer sudo dnf downgrade portainer-<VERSION_BEFORE_2.39.0> sudo dnf versionlock add portainer

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-55761?

portainer: upgrade to 2.39.4, 2.43.0. Exact commands for each OS are on this page.

Is CVE-2026-55761 being exploited?

CVE-2026-55761 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-55761 affect?

CVE-2026-55761 affects portainer. Severity is medium (CVSS 5.9). 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, unau

How urgent is CVE-2026-55761?

Priority 41/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Docker vulnerabilities · Kubernetes vulnerabilities

References

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