Cilium host policy bypass in endpoint-routes mode with dual-stack

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

3.3 · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact This vulnerability allows bypassing host policies for IPv6 traffic coming from a Cilium-managed pod and destined to the host-network namespace (e.g., to a host-network pod). Host policy enforcement on IPv4 or for traffic coming from outside the node is not affected. Cilium is only affected by this vulnerability if IPv4, IPv6, endpoint routes, and the host firewall are enabled. Note that endpoint routes are typically only enabled in GKE, EKS, AKS, and OpenShift; in those environments, IPv6 is typically disabled. Host firewall is disabled by default. Patches The bug is fixed in versions v1.10.13 and v1.11.7 of Cilium. Workarounds For affected users who can't upgrade, one potential workaround is to ensure all pods have network policies that prevent sending arbitrary traffic to the local node. References Commit fixing the vulnerability: https://github.com/cilium/cilium/commit/c758da7e9d19cd19b96dc90424c0b5ec7409cd0a. For more information If you have any questions or comments about…

Published by the source

15 Jul 2022, 21:46 UTC

Last modified by the source

12 Jan 2023, 05:02 UTC

Source last checked

26 Oct 2026, 14:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-wc5v-r48v-g4vh

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# Patch Next advisory brief: GHSA-wc5v-r48v-g4vh

Advisory: Cilium host policy bypass in endpoint-routes mode with dual-stack
IDs: GHSA-wc5v-r48v-g4vh
Record: https://patchnext.com/advisories/ghsa-wc5v-r48v-g4vh (revision 1, source checked 26 Oct 2026, 14:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/cilium/cilium 1.11.7, 1.10.13. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/cilium/cilium: affected < 1.10.13; >= 1.11.0, < 1.11.7; fixed in 1.10.13, 1.11.7

## Suggested inspection (read-only)
- Go github.com/cilium/cilium: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/cilium/cilium.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-wc5v-r48v-g4vh (GitHub-reviewed advisory GHSA-wc5v-r48v-g4vh lists affected ranges: Go github.com/cilium/cilium >=0 =1.11.0 <1.11.7)

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