CVE-2026-33343 etcd: Nested etcd transactions bypass RBAC authorization checks
Authenticated users can bypass RBAC key restrictions via nested transactions, accessing the entire etcd data store.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-33343?
CVE-2026-33343 is a missing authorization vulnerability in etcd-io etcd, published on 26 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-863
Which versions are affected by CVE-2026-33343?
11 open source packages ship an affected version, including go.etcd.io/etcd/v3, etcd and go.etcd.io/etcd. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
go.etcd.io/etcd/v3 Go | All versions | 3.4.42, 3.5.28, 3.6.9 |
go.etcd.io/etcd/v3 Go | All versions | 3.4.42 |
go.etcd.io/etcd/v3 Go | All versions | 3.4.42 |
go.etcd.io/etcd/v3 Go | From 3.5.0-alpha.0 | 3.5.28 |
go.etcd.io/etcd/v3 Go | From 3.5.0-alpha.0 | 3.5.28 |
go.etcd.io/etcd/v3 Go | From 3.6.0-alpha.0 | 3.6.9 |
5 more packages
go.etcd.io/etcd/v3 Go | From 3.6.0-alpha.0 | 3.6.9 |
etcd Bitnami | All versions | 3.4.42, 3.5.28, 3.6.9 |
go.etcd.io/etcd Go | All versions | None |
go.etcd.io/etcd Go | All versions to 3.3.27 | None |
go.etcd.io/etcd Go | All versions to 3.3.27 | None |
Products include Etcd Etcd.
How do I fix CVE-2026-33343?
Upgrade go.etcd.io/etcd/v3 to a fixed version for your release line: 3.4.42, 3.5.28 or 3.6.9.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-33343 being exploited?
There is no known exploitation of CVE-2026-33343 in the wild and no public exploit code.
Other vulnerabilities in etcd-io etcd
- CVE-2021-28235 Etcd-io Improper Authentication vulnerability
- CVE-2026-33413 etcd: Authorization bypasses in multiple APIs
- CVE-2022-34038 Denial of service in n/a
- CVE-2018-16886 go.etcd.io/etcd Authentication Bypass
- CVE-2026-59818 etcd: gRPC client listener does not enforce `--client-crl-file` certificate revocation
Sources
Also known as AZL-80954, BIT-etcd-2026-33343, DEBIAN-CVE-2026-33343, GHSA-rfx7-8w68-q57q, GO-2026-4808, MINI-29wg-66qg-qc26 and 6 more.