# CVE-2018-16886: GO-2021-0077 - Authentication bypass in go.etcd.io/etcd

Source: https://junglewise.ai/threats/cve-2018-16886-go-etcd-io-etcd-authentication-bypass  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-04-14  
License: CC BY 4.0 with a link back

CVE-2018-16886 · Severity: low · CVSS 3.1 · Published 2021-04-14

Authentication bypass in go.etcd.io/etcd

Technologies: [go.etcd.io/etcd (Go)](https://junglewise.ai/threats/technologies/go-etcd-io-etcd), [go.etcd.io/etcd/v3 (Go)](https://junglewise.ai/threats/technologies/go-etcd-io-etcd-v3). Vendors: [Go](https://junglewise.ai/threats/vendors/go).

## Quick answers

**Is CVE-2018-16886 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2018-16886 being exploited in the wild.

**How severe is CVE-2018-16886?** Low severity, with a CVSS score of 3.1, published 14 April 2021.

**Which products and versions are affected?** go.etcd.io/etcd (Go) SEMVER:introduced=0,fixed=0.5.0-alpha.5.0.20190108173120-83c051b701d3; go.etcd.io/etcd/v3 (Go) SEMVER:introduced=3.2.0,fixed=3.2.26.

**Is there a fix for CVE-2018-16886?** Yes. go.etcd.io/etcd (Go): upgrade to 0.5.0-alpha.5.0.20190108173120-83c051b701d3 or later; go.etcd.io/etcd/v3 (Go): upgrade to 3.2.26 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2018-16886?** Check whether you run go.etcd.io/etcd (Go) or go.etcd.io/etcd/v3 (Go) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- go.etcd.io/etcd (Go): upgrade to 0.5.0-alpha.5.0.20190108173120-83c051b701d3 or later

  ```sh
  go get go.etcd.io/etcd@v0.5.0-alpha.5.0.20190108173120-83c051b701d3
  ```

- go.etcd.io/etcd/v3 (Go): upgrade to 3.2.26 or later

  ```sh
  go get go.etcd.io/etcd/v3@v3.2.26
  ```


## Affected products

- go.etcd.io/etcd (Go) SEMVER:introduced=0,fixed=0.5.0-alpha.5.0.20190108173120-83c051b701d3
- go.etcd.io/etcd/v3 (Go) SEMVER:introduced=3.2.0,fixed=3.2.26

## Identifiers

- CVE-2018-16886
- GHSA-h6xx-pmxh-3wgp
- GO-2021-0077

## Related threats

- [etcd TLS listener denial of service via connection exhaustion](https://junglewise.ai/threats/cve-2026-73500-etcd-tls-listener-denial-of-service-via-connection-exhaustion)
- [etcd authorization bypass in Watch gRPC API](https://junglewise.ai/threats/cve-2026-73499-etcd-authorization-bypass-in-watch-grpc-api)
- [etcd RBAC authorization bypass in transaction operations](https://junglewise.ai/threats/cve-2026-44283-etcd-rbac-authorization-bypass-in-transaction-operations)
- [GO-2026-4808 - Nested etcd transactions bypass RBAC authorization checks in go.etcd.io/etcd](https://junglewise.ai/threats/cve-2026-33343-etcd-nested-etcd-transactions-bypass-rbac-authorization-checks)
- [GO-2026-4806 - Authorization bypasses in multiple APIs in go.etcd.io/etcd](https://junglewise.ai/threats/cve-2026-33413-etcd-authorization-bypasses-in-multiple-apis)