Vulnerability · Published Mar 26, 2026 · Assigned by GitHub_M
CVE-2026-33343etcd: Nested etcd transactions bypass RBAC authorization checks
None 0.0
In plain English
A incorrect authorization in etcd from etcd-io. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | etcd | 3.6.10-r0 | ALPINE-CVE-2026-33343 |
| Alpine:v3.24 | etcd | 3.6.10-r0 | ALPINE-CVE-2026-33343 |
| Debian:12 | etcd | no fix listed | DEBIAN-CVE-2026-33343 |
| Debian:13 | etcd | no fix listed | DEBIAN-CVE-2026-33343 |
| Debian:14 | etcd | 3.5.16-11 | DEBIAN-CVE-2026-33343 |
| Go | go.etcd.io/etcd | no fix listed | GO-2026-4808 |
| Go | go.etcd.io/etcd | no fix listed | GHSA-rfx7-8w68-q57q |
| Go | go.etcd.io/etcd/v3 | 3.4.42 | GHSA-rfx7-8w68-q57q |
| Go | go.etcd.io/etcd/v3 | 3.4.42, 3.5.28, 3.6.9 | GO-2026-4808 |
| Go | go.etcd.io/etcd/v3 | 3.6.9 | GHSA-rfx7-8w68-q57q |
| Go | go.etcd.io/etcd/v3 | 3.5.28 | GHSA-rfx7-8w68-q57q |
| Ubuntu:25.10 | etcd | no fix listed | UBUNTU-CVE-2026-33343 |
| Ubuntu:26.10 | etcd | no fix listed | UBUNTU-CVE-2026-33343 |
Affected products (as reported)
Weakness: CWE-863 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N
References
- https://github.com/etcd-io/etcd/security/advisories/GHSA-rfx7-8w68-q57q x_refsource_CONFIRM