CVE-2025-23047: Github.com/cilium/cilium Cilium Has An Information Leakage Vulnerability

MODERATE
Advisory Identifier: GHSA-h78m-j95m-5356
CVSS 6.5
CWE-200
Published
Advisory Summary

CVE-2025-23047 is a MODERATE (CVSS 6.5) cilium has an information leakage vulnerability (CWE-200: Exposure of Sensitive Information to an Unauthorized Actor) affecting Github.com/cilium/cilium libraries in the Go ecosystem. The issue involves cilium has an information leakage via insecure default hubble ui cors header. Remediation is available by upgrading affected packages to version 1.14.19, 1.15.13, 1.16.6.

CVE-2025-23047 at a Glance

CVE Identifier CVE-2025-23047
GHSA Identifier GHSA-h78m-j95m-5356
Severity MODERATE
CVSS v3.1 Base Score 6.5
CWE Classification CWE-200: Exposure of Sensitive Information to an Unauthorized Actor
Affected Product Github.com/cilium/cilium
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2025-23047

To remediate this vulnerability, upgrade all affected Github.com/cilium/cilium dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/cilium/cilium fixed: 1.14.19
Upgrade github.com/cilium/cilium to 1.14.19
github.com/cilium/cilium fixed: 1.15.13
Upgrade github.com/cilium/cilium to 1.15.13
github.com/cilium/cilium fixed: 1.16.6
Upgrade github.com/cilium/cilium to 1.16.6
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for github.com/cilium/cilium

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-23047, inspect your project dependencies for Github.com/cilium/cilium:

inspect dependencies for github.com/cilium/cilium

Analyze the terminal output to locate any version of Github.com/cilium/cilium in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.14.19), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor, where the product exposes sensitive information to an actor that is not explicitly authorized to have access to that information. In Github.com/cilium/cilium, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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. ### Patches 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 ### 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](https://github.com/cilium/cilium/commit/a3489f190ba6e87b5336ee685fb6c80b1270d06d). ### 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](https://docs.cilium.io/en/latest/community/community/#slack). If you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [security@cilium.io](mailto:security@cilium.io). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

CVE-2025-23047 Affected Github.com/cilium/cilium Versions

3 component(s)
Fixed Versions:
1.14.191.15.131.16.6
Product / Package Ecosystem Affected Versions Fixed Version
github.com/cilium/cilium
Go
≥ 1.14.0
< 1.14.19
1.14.19
github.com/cilium/cilium
Go
≥ 1.15.0
< 1.15.13
1.15.13
github.com/cilium/cilium
Go
≥ 1.16.0
< 1.16.6
1.16.6

References

Frequently Asked Questions

What is CVE-2025-23047?
CVE-2025-23047 is a security vulnerability in Github.com/cilium/cilium involving Cilium has an information leakage via insecure default Hubble UI CORS header under CWE-200: Exposure of Sensitive Information to an Unauthorized Actor.
Which Github.com/cilium/cilium versions are affected?
Affected versions include releases prior to 1.14.19, 1.15.13, 1.16.6 across affected packages: github.com/cilium/cilium.
What version fixes CVE-2025-23047?
Upgrading to 1.14.19, 1.15.13, 1.16.6 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/cilium/cilium affected?
Yes, github.com/cilium/cilium is affected in releases prior to 1.14.19, 1.15.13, 1.16.6. Upgrade your dependency to 1.14.19, 1.15.13, 1.16.6 or later.
What is the CVSS score of CVE-2025-23047?
CVE-2025-23047 has a CVSS v3.1 base score of 6.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N.
What CWE is associated with CVE-2025-23047?
CVE-2025-23047 is classified under 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 can I check Go dependencies for CVE-2025-23047?
Run the dependency tree command: 'inspect dependencies for github.com/cilium/cilium'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-h78m-j95m-5356",
  "modified" : "2025-01-22T18:44:37Z",
  "published" : "2025-01-22T18:09:27Z",
  "aliases" : [ "CVE-2025-23047" ],
  "summary" : "Cilium has an information leakage via insecure default Hubble UI CORS header",
  "details" : "### Impact\n\nFor 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.\n\n### Patches\n\nThis issue was patched in https://github.com/cilium/cilium/commit/a3489f190ba6e87b5336ee685fb6c80b1270d06d\n\nThis issue affects:\n\n- Cilium between v1.14.0 and v1.14.18 inclusive\n- Cilium between v1.15.0 and v1.15.12 inclusive\n- Cilium between v1.16.0 and v1.16.5 inclusive\n\nThis issue is patched in:\n\n- Cilium v1.14.19\n- Cilium v1.15.13\n- Cilium v1.16.6\n\n### Workarounds\n\nUsers who deploy Hubble UI using the Cilium Helm chart directly can remove the CORS headers from the Helm template as shown in the [patch](https://github.com/cilium/cilium/commit/a3489f190ba6e87b5336ee685fb6c80b1270d06d).\n\n### Acknowledgements\n\nThe 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.\n\n### For more information\nIf you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack).\n\nIf you think you have found a vulnerability affecting Cilium, we strongly encourage you to report it to our security mailing list at [security@cilium.io](mailto:security@cilium.io). This is a private mailing list for the Cilium security team, and your report will be treated as top priority.\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cilium/cilium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.14.0"
      }, {
        "fixed" : "1.14.19"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cilium/cilium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.15.0"
      }, {
        "fixed" : "1.15.13"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/cilium/cilium"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.16.0"
      }, {
        "fixed" : "1.16.6"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/cilium/cilium/security/advisories/GHSA-h78m-j95m-5356"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-23047"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/cilium/cilium/commit/a3489f190ba6e87b5336ee685fb6c80b1270d06d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/cilium/cilium"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-01-22T18:09:27Z",
    "nvd_published_at" : "2025-01-22T18:15:21Z"
  }
}