CVE-2018-16886

28

FAUCET Score

CVE-2018-16886 describes an improper authentication vulnerability in etcd versions 3.2.x before 3.2.26 and 3.3.x before 3.3.11, specifically when RBAC and client-cert-auth are enabled. This flaw allows a remote attacker to authenticate as an existing RBAC user if their client TLS certificate's Common Name matches a valid username, even with any trusted client certificate, impacting etcd, Fedora, and Red Hat products. The vulnerability carries a high CVSS score of 8.1, indicating a network-based attack with high impact on confidentiality, integrity, and availability, but requires high attack complexity. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage surrounding this CVE.

Impacted Technologies

Vendor	Product	Version(s)	CPE
		>= 3.2.0, < 3.2.26CPE matchmatch criteria	cpe:2.3:a:etcd:etcd::::::::
		>= 3.3.0, < 3.3.11CPE matchmatch criteria	cpe:2.3:a:etcd:etcd::::::::
		7.0CPE matchmatch criteria	cpe:2.3:o:redhat:enterprise_linux_desktop:7.0:::::::*
		7.0CPE matchmatch criteria	cpe:2.3:o:redhat:enterprise_linux_server:7.0:::::::*
		7.0CPE matchmatch criteria	cpe:2.3:o:redhat:enterprise_linux_workstation:7.0:::::::*

CVSS Data

CVSS version used by this source: 3.0

6.8MEDIUM

CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Attack Vector

NETWORK

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

NONE

Exploitability Score

1.6

Impact Score

5.2

CvssVersion

3.0

Exploit Intelligence

EPSS Score

4.03%

Probability of exploitation in next 30 days

EPSS Percentile

89.5%

Percentile rank of EPSS score among Peer Group

As of 2026-07-26

Model: v2026.06.15

This CVE's current EPSS score of 0.0403 is in the 53rd percentile among its peer group of 8,914 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.1 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.2 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (6)

gopatch availablevia ghsa

Product: go.etcd.io/etcd/v3Fixed in: 3.2.26

gopatch availablevia ghsa

Product: go.etcd.io/etcd/v3Fixed in: 3.3.11

gopatch availablevia ghsa

Product: go.etcd.io/etcdFixed in: 0.5.0-alpha.5.0.20190108173120-83c051b701d3

redhatpatch availablevia nvd_reference

redhatpatch availablevia redhat_api

Product: Red Hat Enterprise Linux 7 ExtrasFixed in: etcd-0:3.2.26-1.el7

redhatend of lifevia redhat_api

Product: Red Hat Storage 3Fixed in: etcd

Vendor Advisories (2)

goGHSA-h6xx-pmxh-3wgphigh

go.etcd.io/etcd Authentication Bypass

redhatCVE-2018-16886Moderate

etcd: Improper Authentication in auth/store.go:AuthInfoFromTLS() via gRPC-gateway

References

access.redhat.com / errata/RHSA-2019:0237

Third Party Advisory

access.redhat.com / errata/RHSA-2019:1352

Third Party Advisory

bugzilla.redhat.com / show_bug.cgi

Issue TrackingPatchThird Party Advisory

github.com / etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.2.md

Release Notes

github.com / etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.3.md

Release Notes

lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/JX7QTIT465BQGRGNCE74RATRQLKT2QE4

lists.fedoraproject.org / archives/list/package-announce%40lists.fedoraproject.org/message/UPGYHMSKDPW5GAMI7BEP3XQRVRLLBJKS

securityfocus.com / bid/106540

Third Party AdvisoryVDB Entry