Headline
GHSA-38pp-6gcp-rqvm: Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic
Impact
CiliumNetworkPolicys which use egress.toGroups.aws.securityGroupsIds to reference AWS security group IDs that do not exist or are not attached to any network interface may unintentionally allow broader outbound access than intended by the policy authors. In such cases, the toCIDRset section of the derived policy is not generated, which means outbound traffic may be permitted to more destinations than originally intended.
Patches
This issue has been patched in:
- Cilium v1.18.4
- Cilium v1.17.10
- Cilium v1.16.17
This issue affects:
- Cilium v1.18 between v1.18.0 and v1.18.3 inclusive
- Cilium v1.17 between v1.17.0 and v1.17.9 inclusive
- Cilium v1.16.16 and below
Workarounds
There is no workaround to this issue.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @SeanEmac for reporting this issue and to @fristonio for the patch.
For more information
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.
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2025-64715
Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic
Moderate severity GitHub Reviewed Published Nov 27, 2025 in cilium/cilium • Updated Dec 1, 2025
Package
gomod Ciliumgithub.com/cilium/cilium (Go)
Affected versions
>= 1.17.0, < 1.17.10
gomod github.com/cilium/cilium (Go)
>= 1.18.0, < 1.18.4
< 1.16.17
Impact
CiliumNetworkPolicys which use egress.toGroups.aws.securityGroupsIds to reference AWS security group IDs that do not exist or are not attached to any network interface may unintentionally allow broader outbound access than intended by the policy authors. In such cases, the toCIDRset section of the derived policy is not generated, which means outbound traffic may be permitted to more destinations than originally intended.
Patches
This issue has been patched in:
- Cilium v1.18.4
- Cilium v1.17.10
- Cilium v1.16.17
This issue affects:
- Cilium v1.18 between v1.18.0 and v1.18.3 inclusive
- Cilium v1.17 between v1.17.0 and v1.17.9 inclusive
- Cilium v1.16.16 and below
Workarounds
There is no workaround to this issue.
Acknowledgements
The Cilium community has worked together with members of Isovalent to prepare these mitigations. Special thanks to @SeanEmac for reporting this issue and to @fristonio for the patch.
For more information
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.
References
- GHSA-38pp-6gcp-rqvm
- https://nvd.nist.gov/vuln/detail/CVE-2025-64715
- cilium/cilium@a385856
- https://github.com/cilium/cilium/releases/tag/v1.16.17
- https://github.com/cilium/cilium/releases/tag/v1.17.10
- https://github.com/cilium/cilium/releases/tag/v1.18.4
Published to the GitHub Advisory Database
Dec 1, 2025