CVE-2018-16886

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.

• CWE-287
• CWE-287

• 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/

Published

Jan 14, 2019

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2018-16880A flaw was found in the Linux kernel's handle_rx() function …7
• CVE-2018-16881A denial of service vulnerability was found in rsyslog in th…7.5
• CVE-2018-16882A use-after-free issue was found in the way the Linux kernel…8.8
• CVE-2018-16883sssd versions from 1.13.0 to before 2.0.0 did not properly r…2.5
• CVE-2018-16884A flaw was found in the Linux kernel's NFS41+ subsystem. NFS…8
• CVE-2018-16885A flaw was found in the Linux kernel that allows the userspa…4.7
• CVE-2018-16887A cross-site scripting (XSS) flaw was found in the katello c…5.4
• CVE-2018-16888It was discovered systemd does not correctly check the conte…4.7
• CVE-2018-16889Ceph does not properly sanitize encryption keys in debug log…5.5
• CVE-2018-16890libcurl versions from 7.36.0 to before 7.64.0 is vulnerable …7.5
• CVE-2018-16891Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…
• CVE-2018-16892Rejected reason: DO NOT USE THIS CANDIDATE NUMBER. ConsultID…