CVE-2025-64715 is a medium-severity (CVSS 4) CWE-284 vulnerability in github.com/cilium/cilium. A fix is available for github.com/cilium/cilium — see the affected versions and patch details below.
Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-64715.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2025-64715 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
github.com/cilium/cilium🐹github.com/cilium/cilium🐹github.com/cilium/ciliumReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
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 [email protected]. This is a private mailing list for the Cilium security team, and your report will be treated as top priority.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/cilium/cilium | ≥ 1.18.0&&< 1.18.4 | 1.18.4go get github.com/cilium/cilium@v1.18.4 |
| 🐹Go | github.com/cilium/cilium | ≥ 1.17.0&&< 1.17.10 | 1.17.10go get github.com/cilium/cilium@v1.17.10 |
| 🐹Go | github.com/cilium/cilium | all versions | 1.16.17go get github.com/cilium/cilium@v1.16.17 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/cilium/cilium, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update github.com/cilium/cilium to 1.18.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-64715 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-64715 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-64715. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-64715 in your dependencies?
O3 Security finds CVE-2025-64715 across Go dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.