GitHub Advisoryadvisory · Go

GHSA-gj49-89wh-h4gj Cillium exposes sensitive information included in the cilium-bugtool debug archive

HIGH Published 2026-04-25 Modified 2026-05-13 Official page ↗
Aliases
CVE-2026-41520
Ecosystem
Go
Packages
github.com/cilium/cilium
Severity
High
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
Weaknesses
CWE-200, CWE-312
Reviewed
2026-04-25

Affected packages

• Go github.com/cilium/cilium: < 1.17.15 → fixed in 1.17.15 • Go github.com/cilium/cilium: >= 1.18.0, < 1.18.9 → fixed in 1.18.9 • Go github.com/cilium/cilium: >= 1.19.0, < 1.19.3 → fixed in 1.19.3

Description

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 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 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 [email protected]. This is a private mailing list for the Cilium security team, and the report will be treated as top priority.

Related

Alias · CVE (1)

  • CVE-2026-41520 Cilium is a networking, observability, and security solution with an eBPF-based dataplane. vulnerability

Weakness · CWE (2)

  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor weakness
  • CWE-312 Cleartext Storage of Sensitive Information weakness

References