How severe is CVE-2026-26963?

CVE-2026-26963 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-26963 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-26963?

CVE-2026-26963 affects Cilium. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-26963?

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

Does CVE-2026-26963 have an EU (EUVD) identifier?

Yes. CVE-2026-26963 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8407.

When was CVE-2026-26963 published?

CVE-2026-26963 was published on 2026-02-20 and last updated on 2026-06-17.

CVE-2026-26963

CVE-2026-26963 is a medium-severity vulnerability in Cilium with a CVSS 3.x base score of 6.1. 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 6.1)
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-8407
Weakness: CWE-863
Affected product: Cilium
Published: 2026-02-20
Last modified: 2026-06-17

Description

Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Versions 1.18.0 through 1.18.5 will incorrectly permit traffic from Pods on other nodes when Native Routing, WireGuard and Node Encryption are enabled. This issue has been fixed in version 1.18.6.

Frequently asked questions

What is CVE-2026-26963?: Cilium is a networking, observability, and security solution with an eBPF-based dataplane. Versions 1.18.0 through 1.18.5 will incorrectly permit traffic from Pods on other nodes when Native Routing, WireGuard and Node Encryption are enabled. This issue has been fixed in version 1.18.6.
How severe is CVE-2026-26963?: CVE-2026-26963 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-26963 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-26963?: CVE-2026-26963 affects Cilium. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-26963?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-26963 have an EU (EUVD) identifier?: Yes. CVE-2026-26963 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-8407.
When was CVE-2026-26963 published?: CVE-2026-26963 was published on 2026-02-20 and last updated on 2026-06-17.

References

Affected products (1)

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

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