The output of cilium-bugtool can contain sensitive data when the tool is run against Cilium deployments with WireGuard encryption enabled.
Users of WireGuard Transparent Encryption are affected.
The sensitive data is the WireGuard private key (cilium_wg0.key) used for node-to-node encrypted communication
cilium-bugtool is a debugging tool that is typically invoked manually and does not run during the normal operation of a Cilium cluster. It is also invoked when gathering sysdumps using the Cilium CLI's cilium sysdump command.
This issue affects:
This issue has been patched in:
There is no workaround to this issue.
Users who have previously shared bugtool or sysdump archives from WireGuard-enabled nodes should rotate the WireGuard keys on the affected nodes. This can be done by deleting the key file and restarting the Cilium agent, which will generate a new key pair.
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Cillium extends special thanks to @kodareef5 for reporting the issue and @tklauser for their work on triaging and remediating this issue.
If there are any questions or comments about this advisory, please reach out on Slack.
Cilium strongly encourages the reporting of suspected vulnerabilities to the security mailing list at security@cilium.io. This is a private mailing list for the Cilium security team, and the report will be treated as top priority.
{
"cwe_ids": [
"CWE-200",
"CWE-312"
],
"github_reviewed": true,
"github_reviewed_at": "2026-04-25T23:39:37Z",
"nvd_published_at": "2026-05-08T23:16:35Z",
"severity": "HIGH"
}