CVE-2026-21891

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Source

https://cve.org/CVERecord?id=CVE-2026-21891

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21891.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-21891

Aliases

GHSA-xj93-qw9p-jxq4

Published

2026-01-08T14:00:14.578Z

Modified

2026-03-14T12:47:08.194220Z

Severity

9.4 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L CVSS Calculator

Summary

ZimaOS has Authentication Bypass via System-Level Username

Details

ZimaOS is a fork of CasaOS, an operating system for Zima devices and x86-64 systems with UEFI. In versions up to and including 1.5.0, the application checks the validity of the username but appears to skip, misinterpret, or incorrectly validate the password when the provided username matches a known system service account. The application's login function fails to properly handle the password validation result for these users, effectively granting authenticated access to anyone who knows one of these common usernames and provides any password. As of time of publication, no known patched versions are available.

Database specific

{
    "cna_assigner": "GitHub_M",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/21xxx/CVE-2026-21891.json",
    "cwe_ids": [
        "CWE-287"
    ]
}

References

Affected packages

Git / github.com/icewhaletech/zimaos

Affected ranges

Type

GIT

Repo

https://github.com/icewhaletech/zimaos

Events

Introduced

Last affected

76df65ac82f85bc318fe95556ffb67decde3ae2b

Database specific

{
    "versions": [
        {
            "introduced": "0"
        },
        {
            "last_affected": "1.5.0"
        }
    ]
}

Affected versions

0.*

0.4.8

0.4.8.1

0.4.9

0.4.9.1

0.4.9.2

0.4.9.3

0.4.9.4

0.5.0

1.*

1.0.0

1.1.0

1.2.2

1.2.3

1.2.3-beta1

1.2.4

1.2.4-beta1

1.2.4-beta2

1.2.5

1.2.5-beta1

1.2.5-beta2

1.2.5-beta3

1.3.0

1.3.0-1

1.3.0-2

1.3.0-beta1

1.3.1

1.3.1-1

1.3.1-beta1

1.3.2

1.3.2-1

1.3.2-beta1

1.3.2-beta2

1.3.3

1.3.3-beta1

1.4.0

1.4.0-beta1

1.4.0-beta2

1.4.1

1.4.1-beta1

1.4.1-beta2

1.4.2

1.4.2-beta1

1.4.2-beta2

1.4.3

1.4.4

1.4.4-1

1.4.4-beta1

1.5.0

1.5.0-beta1

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-21891.json"