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.
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.
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.
### Impact
_What kind of vulnerability is it? Who is impacted?_
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.
### Patches
_Has the problem been patched? What versions should users upgrade to?_
This vulnerability is patched in the following versions:
* etcd 3.6.9
* etcd 3.5.28
* etcd 3.4.42
### Workarounds
_Is there a way for users to fix or remediate the vulnerability without upgrading?_
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
* require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate
distribution
### Reporters
_Our community helps keep etcd secure_
SIG-Etcd thanks community members Luke Francis and Battulga Byambaa for reporting this vulnerability.
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Mar 26, 2026, 1:23:48 PM
dateUpdated: Mar 26, 2026, 6:25:09 PM
2 related source bulletins · separate from aliases
WID-SEC-W-2026-0818: etcd: Mehrere Schwachstellen ermöglichen Umgehen von Sicherheitsvorkehrungen
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-863
Original publisher date fields
published: 2026-03-26T14:16:13.137
lastModified: 2026-06-17T10:37:20.833
1 source CPE criteria · context only
cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
No normalized affected-package data is projected for this source revision. The original publisher record may contain additional product and version evidence; this does not establish that a package is unaffected.