Cillium exposes sensitive information included in the cilium-bugtool debug archive
Date: 2026-04
Affected: go/github.com/cilium/cilium, go/github.com/cilium/cilium, go/github.com/cilium/cilium
Attack vector: info-disclosure
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2026-41520
CWE: CWE-200
CWE-312
CVSS: 7.9 (CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N)

### Impact 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](https://docs.cilium.io/en/stable/security/network/encryption-wireguard/) 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. ### Patches This issue affects: - Cilium v1.19 between v1.19.0 and v1.19.2 inclusive - Cilium v1.18 between v1.18.0 and v1.18.8 inclusive - All versions of Cilium prior to v1.17.15 This issue has been patched in: - Cilium v1.19.3 - Cilium v1.18.9 - Cilium v1.17.15 ### Workarounds 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. ### Acknowledgements 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. ### For more information I


Mitigations:

Architectural layers (MAESTRO):