CVE-2026-33343 (GCVE-0-2026-33343)

Vulnerability from cvelistv5 – Published: 2026-03-26 13:23 – Updated: 2026-03-26 18:25
VLAI
Title
etcd: Nested etcd transactions bypass RBAC authorization checks
Summary
etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42, 3.5.28, and 3.6.9, an authenticated user with RBAC restricted permissions on key ranges can use nested transactions to bypass all key-level authorization. This allows any authenticated user with direct access to etcd to effectively ignore all key range restrictions, accessing the entire etcd data store. Kubernetes does not rely on etcd’s built-in authentication and authorization. Instead, the API server handles authentication and authorization itself, so typical Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice. Restrict network access to etcd server ports so only trusted components can connect and require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.
Severity
0 (None)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-03-26 18:13 UTC
CWE
  • CWE-863 - Incorrect Authorization
Assigner
GitHub_M CNA under the mitre root
CNA scorecard C 72/100 over 7868 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
etcd-io etcd Affected: >= 3.5.0-alpha.0, < 3.5.28
Affected: >= 3.6.0-alpha.0, < 3.6.9
Affected: < 3.4.42
guessed Create a notification for this product.
Show details on NVD website
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