cilium-agent container can access the host via hostPath mount

Exploitation

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

CVSS

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

EPSS

• CVE-2023-27593: 0.22% estimated exploitation activity in the next 30 days; percentile 12.20 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact An attacker with access to a Cilium agent pod can write to /opt/cni/bin due to a hostPath mount of that directory in the agent pod. By replacing the CNI binary with their own malicious binary and waiting for the creation of a new pod on the node, the attacker can gain access to the underlying node. Patches The issue has been fixed and is available on versions =1.11.15, =1.12.8, =1.13.1. Workarounds Kubernetes RBAC should be used to deny users and service accounts exec access to Cilium agent pods. In cases where a user requires exec access to Cilium agent pods, but should not have access to the underlying node, no workaround is possible. References PR containing resolution Acknowledgements The Cilium community has worked together with members of Isovalent and Form3 to prepare these mitigations. Special thanks to Anastasios Koutlis, Daniel Teixeira, and Magdalena Oczadly for their cooperation. For more information If you have any questions or comments about this advisory, please…

Published by the source

17 Mar 2023, 18:20 UTC

Last modified by the source

20 Mar 2023, 12:53 UTC

Source last checked

26 Oct 2026, 14:55 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-4hc4-pgfx-3mrx

Preview the exact text before you copy it. Commands are read-only suggestions; review them before running anything.

# Patch Next advisory brief: CVE-2023-27593

Advisory: cilium-agent container can access the host via `hostPath` mount
IDs: CVE-2023-27593, GHSA-4hc4-pgfx-3mrx
Record: https://patchnext.com/advisories/cve-2023-27593 (revision 1, source checked 26 Oct 2026, 14:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.4)
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 1.13.1, 1.12.8, 1.11.15. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/cilium/cilium: affected < 1.11.15; >= 1.12.0, < 1.12.8; >= 1.13.0, < 1.13.1; fixed in 1.12.8, 1.13.1, 1.11.15

## 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-4hc4-pgfx-3mrx (GitHub-reviewed advisory GHSA-4hc4-pgfx-3mrx lists affected ranges: Go github.com/cilium/cilium >=0 =1.12.0 =1.13.0 <1.13.1)

Commands are suggestions: review each one before running it.