Open-Source Security Intelligence

Know every vulnerability
before it knows you.

DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.

Search

GHSA-4xp2-w642-7mcx

MediumCVSS 6.9 / 10
Published Sep 27, 2023·Last modified Feb 4, 2026
Affected Components(0)

No affected components available

Description

Impact

An attacker with the ability to create or modify CiliumNetworkPolicy objects in a particular namespace is able to affect traffic on an entire Cilium cluster, potentially bypassing policy enforcement in other namespaces.

By using a crafted endpointSelector that uses the DoesNotExist operator on the reserved:init label, the attacker can create policies that bypass namespace restrictions and affect the entire Cilium cluster. This includes potentially allowing or denying all traffic.

This attack requires API server access, as described in the Kubernetes API Server Attacker section of the Cilium Threat Model.

Patches

This issue was patched in https://github.com/cilium/cilium/pull/28007

This issue affects:

  • Cilium <= v1.14.1
  • Cilium <= v1.13.6
  • Cilium <= v1.12.13

This issue has been resolved in:

  • Cilium v1.14.2
  • Cilium v1.13.7
  • Cilium v1.12.14

Workarounds

An admission webhook can be used to prevent the use of endpointSelectors that use the DoesNotExist operator on the reserved:init label in CiliumNetworkPolicies.

Acknowledgements

The Cilium community has worked together with members of Palantir and Isovalent to prepare these mitigations. Special thanks to @odinuge for reporting this issue and @joestringer for the fix.

For more information

If you have any questions or comments about this advisory, please reach out on Slack.

If you think you have found a vulnerability in Cilium, we strongly encourage you to report it to our private security mailing list at security@cilium.io first, before disclosing it in any public forum. This is a private mailing list for Cilium's internal security team, and your report will be treated as top priority.

Risk Scores
Base Score
6.9

The vulnerability can be exploited over a local network, such as Wi-Fi. It is easy for an attacker to exploit this vulnerability. An attacker needs high-level or administrative privileges. No user interaction is needed for the attacker to exploit this vulnerability. The vulnerability can affect other systems as well, not just the initial system. There is a low impact on the confidentiality of the information. There is a high impact on the availability of the system.

Threat Intelligence
6.3

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.41%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

Browse More

Scan your project

Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.

Checkout DevGuard