CVE-2026-26963
Published: 20 February 2026
Summary
CVE-2026-26963 is a medium-severity Incorrect Authorization (CWE-863) vulnerability in Cilium Cilium. Its CVSS base score is 6.1 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Disable or Modify System Firewall (T1686); ranked at the 2.6th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8407
Vulnerability details
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…
more
version 1.18.6.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Authorization bypass in Cilium networking policies with WireGuard/node encryption directly enables unauthorized cross-node traffic, impairing network firewall controls.
Affected Assets
Mitigating Controls
Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Periodic review and update of procedures reduces incorrect authorization implementations over time.
Supervision identifies cases where authorization logic incorrectly permits unauthorized actions.
Defining permitted attribute values and auditing modifications reduces the chance of incorrect authorization outcomes due to tampered or missing labels.
The authorization process and usage restrictions help prevent incorrect authorization for remote access types.
Establishing configuration and connection requirements helps ensure correct rather than incorrect authorization for wireless access.
Establishing connection authorization processes for mobile devices helps ensure authorization decisions are correctly implemented rather than incorrect.
Monitoring account use, notifying on changes, and reviewing accounts for compliance corrects incorrect authorization assignments.
Ensures authorization decisions for external system use are correctly implemented and enforced.