7.1

CVE-2026-55761: portainer Improper Authentication

CVSS: 7.1v4.0HighAnalyzed
AliasesGHSA-x626-fcwx-f5pcGO-2026-6324
Published 08-07-2026Last modified 08-07-2026
Open JSON

Vulnerability summary

CVE-2026-55761 is a high (CVSS 7.1) Improper Authentication vulnerability in portainer. EPSS estimates a 0.49% chance of exploitation in the next 30 days, higher than 41.3% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
38/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.1/10
010
High · v4.0 (CVE.org)
EPSS score
0.49%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 3 · Related 3
OPENSUSE-SU-2026:21812-1SUSE-SU-2026:23692-1SUSE-SU-2026:23712-1

Timeline

  1. 08-07-2026
    PublishedVulnerability first disclosed.
  2. 08-07-2026
    Last modifiedVulnerability information updated.

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 metrics

5 scores · 3 sources · 2 versions

EPSS trend

Probability

0.49%

Chance of exploitation in the next 30 days

Percentile

41%

Versus all other CVEs

30-day change

0.00 pp

From 0.49% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.49%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Portainer

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Github.com/portainer1 product
  • portainer≥ 2.39.0, < 2.39.4 | ≥ 2.40.0, < 2.43.0 | All versions (No fix recorded)
Portainer1 product
  • portainer≥ 2.39.0, < 2.39.4 | ≥ 2.40.0, < 2.43.0

2 vendors · 2 products

References

8 links