Authenticated datastore access via nested transaction authorization bypass
Published Mar 26, 2026 · Updated Mar 26, 2026
Authorization bypass in etcd before 3.4.42, 3.5.28, and 3.6.9 allows remote authenticated users to access all stored key ranges. The server's nested-transaction authorization path fails to apply key-level RBAC checks to operations embedded inside another transaction. Exploitation requires direct access to an etcd cluster using built-in Auth; typical Kubernetes control-plane deployments do not use that authorization path.
Summary
What happened
Authorization bypass in etcd before 3.4.42, 3.5.28, and 3.6.9 allows remote authenticated users to access all stored key ranges. The server's nested-transaction authorization path fails to apply key-level RBAC checks to operations embedded inside another transaction. Exploitation requires direct access to an etcd cluster using built-in Auth; typical Kubernetes control-plane deployments do not use that authorization path.
The record
- CVE
- CVE-2026-33343
- Published
- Mar 26, 2026
- Updated
- Mar 26, 2026
- Vendor
- etcd-io
- Product
- etcd
- Classifications
- CWE-863, T1210
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 26, 2026CVE publishedPublication date reported by the CVE source.
- Mar 26, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 3.4.42
- Affected versionversion=>= 3.5.0-alpha.0, < 3.5.28
- Affected versionversion=>= 3.6.0-alpha.0, < 3.6.9
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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