Summary
Workarounds
Users who deploy Hubble UI using the Cilium Helm chart directly can remove the CORS headers from the Helm template as shown in the patch.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @ciffelia for reporting this issue and to @geakstr for the fix.
For more information
If you have any questions or comments about this advisory, please reach out on Slack.
If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [email protected]. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Impact
For users who deploy Hubble UI using either Cilium CLI or via the Cilium Helm chart, an insecure default Access-Control-Allow-Origin header value could lead to sensitive data exposure. A user with access to a Hubble UI instance affected by this issue could leak configuration details about the Kubernetes cluster which Hubble UI is monitoring, including node names, IP addresses, and other metadata about workloads and the cluster networking configuration. In order for this vulnerability to be exploited, a victim would have to first visit a malicious page.
CVE-2025-23047 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (1.14.19, 1.15.13, 1.16.6); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Remediation advice
This issue was patched in https://github.com/cilium/cilium/commit/a3489f190ba6e87b5336ee685fb6c80b1270d06d
This issue affects:
- Cilium between v1.14.0 and v1.14.18 inclusive
- Cilium between v1.15.0 and v1.15.12 inclusive
- Cilium between v1.16.0 and v1.16.5 inclusive
This issue is patched in:
- Cilium v1.14.19
- Cilium v1.15.13
- Cilium v1.16.6
Frequently Asked Questions
- What is CVE-2025-23047? CVE-2025-23047 is a medium-severity security vulnerability in github.com/cilium/cilium (go), affecting versions >= 1.14.0, < 1.14.19. It is fixed in 1.14.19, 1.15.13, 1.16.6.
- How severe is CVE-2025-23047? CVE-2025-23047 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of github.com/cilium/cilium are affected by CVE-2025-23047? github.com/cilium/cilium (go) versions >= 1.14.0, < 1.14.19 is affected.
- Is there a fix for CVE-2025-23047? Yes. CVE-2025-23047 is fixed in 1.14.19, 1.15.13, 1.16.6. Upgrade to this version or later.
- Is CVE-2025-23047 exploitable, and should I be worried? Whether CVE-2025-23047 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-23047 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2025-23047?
- Upgrade
github.com/cilium/ciliumto 1.14.19 or later - Upgrade
github.com/cilium/ciliumto 1.15.13 or later - Upgrade
github.com/cilium/ciliumto 1.16.6 or later
- Upgrade