Cilium vulnerable to information leakage via incorrect ReferenceGrant handling (CVE-2023-34242) | HOL Guard CVE

Low · CVSS 3.4CVE-2023-34242GHSA-R7WR-4W5Q-55M6

Cilium vulnerable to information leakage via incorrect ReferenceGrant handling

Answer in brief

CVE-2023-34242 records a Low severity (CVSS 3.4) vulnerability in Cilium vulnerable to information leakage via incorrect ReferenceGrant handling. The current sources do not mark it as known exploited. The current feed maps github.com/cilium/cilium (go). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 16, 2023Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Aug 7, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Low · CVSS 3.4
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 3.4. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps github.com/cilium/cilium (go). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
github.com/cilium/ciliumgo	>=1.13.0 <1.13.4	1.13.4

Recommended response

Check inventory. Check lockfiles and deployed manifests for github.com/cilium/cilium.
Review the reported fix. Update github.com/cilium/cilium to 1.13.4 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 16, 2023
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Aug 7, 2026

Sources and claim methodology

Upstream source description

### Impact When the [Gateway API](https://docs.cilium.io/en/v1.13/network/servicemesh/gateway-api/gateway-api/) is enabled in Cilium, the absence of a check on the namespace in which a [ReferenceGrant](https://gateway-api.sigs.k8s.io/api-types/referencegrant/) is created could result in Cilium gaining visibility of secrets (including certificates) and services across namespaces. An attacker on an affected cluster can configure Cilium to use cluster secrets or communicate with services that it should not have access to. Gateway API functionality is disabled by default. ### Patches This vulnerability is fixed in Cilium release 1.13.4. Cilium versions <1.13 are not affected. ### 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 @meyskens for investigating and fixing the issue. ### For more information If you have any questions or comments about this advisory, please reach out on [Slack](https://docs.cilium.io/en/latest/community/community/#slack). As usual, if you think you found a related vulnerability, we strongly encourage you to report security vulnerabilities to our private security mailing list: [[email protected]](mailto:[email protected]) - first, before disclosing them in any public forums. This is a private mailing list where only members of the Cilium internal security team are subscribed to, and is treated as top priority.

Quoted source text, attributed separately from HOL analysis.