Improper authentication in etcd:
Priority MEDIUM 42CWE-287Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- High
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 fixed, 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-287.
Summary
etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 are vulnerable to an improper authentication issue when role-based access control (RBAC) is used and client-cert-auth is enabled. If an etcd client server TLS certificate contains a Common Name (CN) which matches a valid RBAC username, a remote attacker may authenticate as that user with any valid (trusted) client certificate in a REST API request to the gRPC-gateway.
Why it matters now
EPSS 0.04064 90th percentileScored 2026-11-07
Fix Partial go.etcd.io/etcd/v3 (Go): 3.2.26, 3.3.11go.etcd.io/etcd (Go): 0.5.0-alpha.5.0.20190108173120-83c051b701d3Red Hat: 1 advisoryRed Hat: 1 fixed, 1 without a fix
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| The etcd Project | etcd: | versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 | — | No fix listed | CNA |
| — | go.etcd.io/etcd/v3 (Go) | 3.2.0 to before 3.2.26 | 3.2.26 | Patch available | GHSA-h6xx-pmxh-3wgp |
| — | go.etcd.io/etcd/v3 (Go) | 3.3.0 to before 3.3.11 | 3.3.11 | Patch available | GHSA-h6xx-pmxh-3wgp |
| — | go.etcd.io/etcd (Go) | before 0.5.0-alpha.5.0.20190108173120-83c051b701d3 | 0.5.0-alpha.5.0.20190108173120-83c051b701d3 | Patch available | GHSA-h6xx-pmxh-3wgp |
- etcd: VendorThe etcd Project Affected versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11 Fixed in — No fix listed CNA
- go.etcd.io/etcd/v3 (Go) Vendor— Affected 3.2.0 to before 3.2.26 Fixed in 3.2.26 Patch available GHSA-h6xx-pmxh-3wgp
- go.etcd.io/etcd/v3 (Go) Vendor— Affected 3.3.0 to before 3.3.11 Fixed in 3.3.11 Patch available GHSA-h6xx-pmxh-3wgp
- go.etcd.io/etcd (Go) Vendor— Affected before 0.5.0-alpha.5.0.20190108173120-83c051b701d3 Fixed in 0.5.0-alpha.5.0.20190108173120-83c051b701d3 Patch available GHSA-h6xx-pmxh-3wgp
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:* | 3.2.0 to before 3.2.26; 3.3.0 to before 3.3.11 | Vulnerable | etcd-io |
| cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* | 7.0 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* | 30 | Vulnerable | Fedoraproject |
- cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:* Versions 3.2.0 to before 3.2.26; 3.3.0 to before 3.3.11 Vulnerable ·etcd-io
- cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_server:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:* Versions 30 Vulnerable ·Fedoraproject
Remediation
- Fix · GHSA-h6xx-pmxh-3wgp go.etcd.io/etcd/v3 (Go) Fixed in 3.2.26 Advisory →
- Fix · GHSA-h6xx-pmxh-3wgp go.etcd.io/etcd/v3 (Go) Fixed in 3.3.11 Advisory →
- Fix · GHSA-h6xx-pmxh-3wgp go.etcd.io/etcd (Go) Fixed in 0.5.0-alpha.5.0.20190108173120-83c051b701d3 Advisory →
Red Hat 1 advisory
- RHSA-2019:1352 Released 2019-06-04 · Red Hat rating Moderateetcd security, bug fix, and enhancement update
- Red Hat Enterprise Linux 7 Extras etcd-3.2.26-1.el7
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Storage 3 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 7 Extras | Fixed | RHSA-2019:1352 |
Not affected: 3 products
- Red Hat Enterprise Linux 7
- Red Hat OpenShift Container Platform 3.11
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2018-16886
- 2026-10-03 Alias added: GHSA-h6xx-pmxh-3wgp
References
Advisory 5
Other 9
- https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.3.md#security-authentication
- https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.2.md#security-authentication
- https://github.com/etcd-io/etcd/pull/10366
- https://github.com/etcd-io/etcd/commit/0191509637546621d6f2e18e074e955ab8ef374d
- https://github.com/etcd-io/etcd/commit/bf9d0d8291dc71ecbfb2690612954e1a298154b2
- https://github.com/etcd-io/etcd
- https://lists.fedoraproject.org/archives/list/[email protected]/message/JX7QTIT465BQGRGNCE74RATRQLKT2QE4
- https://lists.fedoraproject.org/archives/list/[email protected]/message/UPGYHMSKDPW5GAMI7BEP3XQRVRLLBJKS
- https://pkg.go.dev/vuln/GO-2021-0077
Sources
- CVE-2018-16886 · CVE Program
- CVE-2018-16886 · NVD
- FIRST EPSS
- GHSA-h6xx-pmxh-3wgp · GitHub Advisory Database · CC BY 4.0
- CVE-2018-16886 · Red Hat security data · CC BY 4.0
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