GHSA-gj49-89wh-h4gj BIT-cilium-2026-41520 BIT-cilium-operator-2026-41520 BIT-hubble-relay-2026-41520 CVE-2026-41520 GO-2026-5400
Cillium exposes sensitive information included in the cilium-bugtool debug archive
- Severity
- 7.9 / 10
- Medium · CVSS 3.1
- Exploit chance (EPSS)
- 0.08%
- Chance of exploitation in the next 30 days. Higher than 0.10% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
- CWE-312 Cleartext Storage of Sensitive Information
- Fix
1.17.15- Upgrade github.com/cilium/cilium to this version or later
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 security@cilium.io. This is a private mailing list for the Cilium security team, and the report will be treated as top priority.
Affected versions
Go
| Package | Vulnerable | Fixed in |
|---|---|---|
| github.com/cilium/cilium | < 1.17.15 |
1.17.15 |
| github.com/cilium/cilium | >= 1.18.0, < 1.18.9 |
1.18.9 |
| github.com/cilium/cilium | >= 1.19.0, < 1.19.3 |
1.19.3 |
| github.com/cilium/cilium | < 1.17.15>= 1.18.0, < 1.18.9>= 1.19.0, < 1.19.3 |
1.17.151.18.91.19.3 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
github.com/cilium/cilium Go → 1.17.15
- go
go get github.com/cilium/cilium@v1.17.15 && go mod tidy
Severity breakdown
CVSS 3.1 7.9
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- High
- User interaction
- None
- Scope
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Weakness
CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
How to prevent it
- Architecture and Design: Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
CWE-312: Cleartext Storage of Sensitive Information
The product stores sensitive information in cleartext within a resource that might be accessible to another control sphere.
How to prevent it
- Implementation, System Configuration, Operation: When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to encrypt the data at rest. [REF-1297] [REF-1299] [REF-1301]
- Implementation, System Configuration, Operation: In some systems/environments such as cloud, the use of "double encryption" (at both the software and hardware layer) might be required, and the developer might be solely responsible for both layers, instead of shared responsibility with the administrator of the broader system/environment.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-fm8w-2m5w-9j7r Cilium may unexpectedly allow ingress traffic from the local namespace when a Kubernetes NetworkPolicy is configured with an ipBlock match | Medium | Also affects github.com/cilium/cilium |
| GHSA-w7c2-w76w-5hmj Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces | High | Also affects github.com/cilium/cilium |
| GHSA-q6h5-q3q6-f87x CiliumLocalRedirectPolicy addressMatcher allows cross-namespace service traffic hijacking and can break service translation | Medium | Also affects github.com/cilium/cilium |
| GHSA-3fcv-jvfp-m4q9 Cilium vulnerable to sensitive information disclosure and cluster disruption via local Envoy admin socket access | High | Also affects github.com/cilium/cilium |
| GHSA-hxv8-4j4r-cqgv Cilium L7 proxy may bypass Kubernetes NetworkPolicy for same-node traffic | Medium | Also affects github.com/cilium/cilium |
| GHSA-5r23-prx4-mqg3 Cilium may not enforce host firewall policies when Native Routing, WireGuard and Node Encryption are enabled | Medium | Also affects github.com/cilium/cilium |
| GHSA-38pp-6gcp-rqvm Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic | Medium | Also affects github.com/cilium/cilium |
| GHSA-5vxx-c285-pcq4 In Cilium, packets from terminating endpoints may not be encrypted in Wireguard-enabled clusters | Medium | Also affects github.com/cilium/cilium |
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