GHSA-w7c2-w76w-5hmj

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Source
https://github.com/advisories/GHSA-w7c2-w76w-5hmj
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-w7c2-w76w-5hmj/GHSA-w7c2-w76w-5hmj.json
JSON Data
https://api.osv.dev/v1/vulns/GHSA-w7c2-w76w-5hmj
Aliases
Published
2026-09-24T19:38:39Z
Modified
2026-09-24T19:45:04Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:L CVSS Calculator
Summary
Cilium: Namespaced HTTPRoutes can redirect traffic to other namespaces
Details

Impact

In Cilium clusters using Gateway API, users with permissions to create or update namespaced HTTPRoutes can mirror HTTP traffic to any Service in any namespace, bypassing the ReferenceGrant authorization mechanism.

Gateway API functionality is disabled by default.

Patches

This issue affects:

  • Cilium v1.19 from v1.19.0 to v1.19.4 inclusive
  • Cilium v1.18 from v1.18.0 to v1.18.10 inclusive
  • All versions of Cilium before v1.17.17

This issue is patched in:

  • Cilium v1.19.5
  • Cilium v1.18.11
  • Cilium v1.17.17

Workarounds

There is no workaround to this issue. Users of this feature who are unable to upgrade can mitigate the risk by ensuring that RBAC permissions to create HTTPRoute objects are only granted to cluster admins.

Acknowledgements

The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @galanko for reporting the issue and @mhofstetter for their work on triaging and remediating this issue.

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 security@cilium.io. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.

Database specific 
{
    "cwe_ids":  [
        "CWE-862"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-09-24T19:38:39Z",
    "nvd_published_at":  "2026-07-15T20:17:51Z",
    "severity":  "MODERATE"
}
References

Affected packages

Go / github.com/cilium/cilium

Package

Name
github.com/cilium/cilium
View open source insights on deps.dev
Purl
pkg:golang/github.com/cilium/cilium

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.17.17

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-w7c2-w76w-5hmj/GHSA-w7c2-w76w-5hmj.json"

Go / github.com/cilium/ciliumCilium

Package

Name
github.com/cilium/ciliumCilium
View open source insights on deps.dev
Purl
pkg:golang/github.com/cilium/ciliumCilium

Affected ranges

Type
SEMVER
Events
Introduced
1.18.0
Fixed
1.18.11

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-w7c2-w76w-5hmj/GHSA-w7c2-w76w-5hmj.json"

Go / github.com/cilium/cilium

Package

Name
github.com/cilium/cilium
View open source insights on deps.dev
Purl
pkg:golang/github.com/cilium/cilium

Affected ranges

Type
SEMVER
Events
Introduced
1.19.0
Fixed
1.19.5

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-w7c2-w76w-5hmj/GHSA-w7c2-w76w-5hmj.json"