How severe is CVE-2026-55761?

CVE-2026-55761 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2026-55761 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-55761?

CVE-2026-55761 affects Portainer. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-55761?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-55761 published?

CVE-2026-55761 was published on 2026-07-08 and last updated on 2026-07-10.

CVE-2026-55761

CVE-2026-55761 is a medium-severity vulnerability in Portainer with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v4: 7.1
EPSS exploit prediction: 0% (22nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Portainer
Published: 2026-07-08
Last modified: 2026-07-10

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.

Frequently asked questions

What is 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.
How severe is CVE-2026-55761?: CVE-2026-55761 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2026-55761 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (22nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-55761?: CVE-2026-55761 affects Portainer. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-55761?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-55761 published?: CVE-2026-55761 was published on 2026-07-08 and last updated on 2026-07-10.

References

Affected products (1)

cpe:2.3:a:portainer:portainer:*:*:*:*:community:*:*:*

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Other CWE-287 (Improper Authentication) vulnerabilities

CVE-2026-20317 — Critical (CVSS 10.0): As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Workload engineering…
CVE-2026-19977 — Critical (CVSS 10.0): A vulnerability was detected in EFM ipTIME A3004T 14.19.0. The affected element is the function…
CVE-2026-59500 — Critical (CVSS 10.0): CWE-287: Improper Authentication
CVE-2024-27253 — Critical (CVSS 10.0): IBM DOORS Next 7.0.3 through 7.0.3 Interim Fix 018 could allow an authenticated user to bypass security logic to…
CVE-2026-56162 — Critical (CVSS 10.0): Improper authentication in Azure SQL Database allows an unauthorized attacker to elevate privileges over a network.
CVE-2026-62825 — Critical (CVSS 10.0): Improper authentication in Azure Key Vault allows an unauthorized attacker to elevate privileges over a network.

Browse all CWE-287 (Improper Authentication) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

115.190.4.225 (ipv4-addr)
123.25.108.68 (ipv4-addr)
119.91.38.239 (ipv4-addr)
115.190.59.162 (ipv4-addr)
111.229.110.254 (ipv4-addr)
112.155.126.105 (ipv4-addr)
88.168.83.68 (ipv4-addr)
218.239.57.145 (ipv4-addr)