CVE-2018-16886

Name: CVE-2018-16886
Creator: NVD / NIST
Published: 2019-01-14T19:29:00.243+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 4.03%

Last modified Jun 17, 2026

CVE-2018-16886 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. 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.. EPSS estimates a 4.03% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1

8.1/10

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

4.03%

89.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Etcd	Etcd	>= 3.2.0, < 3.2.26
Etcd	Etcd	>= 3.3.0, < 3.3.11
Redhat	Enterprise Linux Desktop	7.0
Redhat	Enterprise Linux Server	7.0
Redhat	Enterprise Linux Workstation	7.0
Fedoraproject	Fedora	30

References

http://www.securityfocus.com/bid/106540Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2019:0237Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:1352Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16886Issue Tracking, Patch, Third Party Advisory
https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.2.md#security-authenticationRelease Notes
https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.3.md#security-authenticationRelease Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JX7QTIT465BQGRGNCE74RATRQLKT2QE4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UPGYHMSKDPW5GAMI7BEP3XQRVRLLBJKS/
http://www.securityfocus.com/bid/106540Third Party Advisory, VDB Entry
https://access.redhat.com/errata/RHSA-2019:0237Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:1352Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16886Issue Tracking, Patch, Third Party Advisory
https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.2.md#security-authenticationRelease Notes
https://github.com/etcd-io/etcd/blob/1eee465a43720d713bb69f7b7f5e120135fdb1ac/CHANGELOG-3.3.md#security-authenticationRelease Notes
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JX7QTIT465BQGRGNCE74RATRQLKT2QE4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UPGYHMSKDPW5GAMI7BEP3XQRVRLLBJKS/

Timeline

Published: Jan 14, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-16886?

How severe is CVE-2018-16886?

CVE-2018-16886 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 4.03% probability of exploitation in the next 30 days.

How do I fix CVE-2018-16886?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-16886?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST