How severe is CVE-2023-27594?

CVE-2023-27594 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2023-27594 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-27594?

CVE-2023-27594 affects Cilium. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-27594?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2023-27594 published?

CVE-2023-27594 was published on 2023-03-17 and last updated on 2026-06-17.

CVE-2023-27594

CVE-2023-27594 is a medium-severity vulnerability in Cilium with a CVSS 3.x base score of 4.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
EPSS exploit prediction: 1% (42nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Cilium
Published: 2023-03-17
Last modified: 2026-06-17

Description

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.11.15, 1.12.8, and 1.13.1, under specific conditions, Cilium may misattribute the source IP address of traffic to a cluster, identifying external traffic as coming from the host on which Cilium is running. As a consequence, network policies for that cluster might be bypassed, depending on the specific network policies enabled. This issue only manifests when Cilium is routing IPv6 traffic and NodePorts are used to route traffic to pods. IPv6 and endpoint routes are both disabled by default. The problem has been fixed and is available on versions 1.11.15, 1.12.8, and 1.13.1. As a workaround, disable IPv6 routing.

Frequently asked questions

What is CVE-2023-27594?: Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Prior to versions 1.11.15, 1.12.8, and 1.13.1, under specific conditions, Cilium may misattribute the source IP address of traffic to a cluster, identifying external traffic as coming from the host on which Cilium is running. As a consequence, network policies for that cluster might be bypassed, depending on the specific network policies enabled. This issue only manifests when Cilium is routing IPv6 traffic and NodePorts are used to route traffic to pods. IPv6 and endpoint routes are both disabled by default. The problem has been fixed and is available on versions 1.11.15, 1.12.8, and 1.13.1. As a workaround, disable IPv6 routing.
How severe is CVE-2023-27594?: CVE-2023-27594 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over an adjacent network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2023-27594 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (42nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-27594?: CVE-2023-27594 affects Cilium. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-27594?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-27594 published?: CVE-2023-27594 was published on 2023-03-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cilium:cilium:*:*:*:*:*:*:*:*

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