CVE-2026-32241

Source
https://cve.org/CVERecord?id=CVE-2026-32241
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-32241.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-32241
Aliases
Downstream
Related
Published
2026-03-27T19:31:48.276Z
Modified
2026-04-10T05:42:55.365448Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
Flannel vulnerable to cross-node remote code execution via extension backend BackendData injection
Details

Flannel is a network fabric for containers, designed for Kubernetes. The Flannel project includes an experimental Extension backend that allows users to easily prototype new backend types. In versions of Flannel prior to 0.28.2, this Extension backend is vulnerable to a command injection that allows an attacker who can set Kubernetes Node annotations to achieve root-level arbitrary command execution on every flannel node in the cluster. The Extension backend's SubnetAddCommand and SubnetRemoveCommand receive attacker-controlled data via stdin (from the flannel.alpha.coreos.com/backend-data Node annotation). The content of this annotation is unmarshalled and piped directly to a shell command without checks. Kubernetes clusters using Flannel with the Extension backend are affected by this vulnerability. Other backends such as vxlan and wireguard are unaffected. The vulnerability is fixed in version v0.28.2. As a workaround, use Flannel with another backend such as vxlan or wireguard.

Database specific
{
    "cwe_ids": [
        "CWE-77"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32241.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/flannel-io/flannel

Affected ranges

Type
GIT
Repo
https://github.com/flannel-io/flannel
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
Database specific
{
    "versions": [
        {
            "introduced": "0"
        },
        {
            "fixed": "0.28.2"
        }
    ]
}

Affected versions

v0.*
v0.10.0
v0.11.0
v0.12.0
v0.13.0
v0.13.0-rc1
v0.13.0-rc2
v0.13.1-rc1
v0.13.1-rc2
v0.14.0
v0.14.0-dual-stack
v0.14.0-rc1
v0.15.0
v0.15.1
v0.16.0
v0.16.1
v0.16.2
v0.16.3
v0.17.0
v0.18.0
v0.18.1
v0.19.0
v0.19.1
v0.19.2
v0.20.0
v0.20.1
v0.20.2
v0.21.0
v0.21.1
v0.21.2
v0.21.3
v0.21.4
v0.21.5
v0.22.0
v0.22.1
v0.22.2
v0.22.3
v0.23.0
v0.24.0
v0.24.1
v0.24.2
v0.24.3
v0.24.4
v0.25.0
v0.25.1
v0.25.2
v0.25.3
v0.25.4
v0.25.5
v0.25.6
v0.25.7
v0.26.0
v0.26.1
v0.26.2
v0.26.3
v0.26.4
v0.26.5
v0.26.6
v0.26.7
v0.27.0
v0.27.1
v0.27.2
v0.27.3
v0.27.4
v0.28.0
v0.28.1
v0.5.0
v0.5.1
v0.5.2
v0.5.3
v0.6.0
v0.6.1
v0.7.0
v0.8.0-rc1
v0.8.0-rc2
v0.9.0
v0.9.0-rc1
v015.*
v015.0-rc1

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-32241.json"