etcd-io etcd up to 3.5.31/3.6.12 gRPC Client Authentication certificate validation

Summaryinfo

A vulnerability identified as problematic has been detected in etcd-io etcd up to 3.5.31/3.6.12. This affects an unknown function of the component gRPC Client Authentication Handler. The manipulation leads to certificate validation. This vulnerability is traded as CVE-2026-59818. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in etcd-io etcd up to 3.5.31/3.6.12. It has been rated as problematic. This issue affects some unknown functionality of the component gRPC Client Authentication Handler. The manipulation with an unknown input leads to a certificate validation vulnerability. Using CWE to declare the problem leads to CWE-295. The product does not validate, or incorrectly validates, a certificate. Impacted is integrity. The summary by CVE is:

etcd is a distributed key-value store for the data of a distributed system. Prior to 3.5.32 and 3.6.13, when etcd is configured with --listen-client-http-urls to split HTTP and gRPC client endpoints onto separate listeners, the --client-crl-file Certificate Revocation List is not enforced on the gRPC listener, allowing a client with a revoked certificate to authenticate successfully over gRPC. This issue is fixed in versions 3.5.32 and 3.6.13.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-59818 since 07/07/2026. The exploitation is known to be difficult. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available. The attack technique deployed by this issue is T1587.003 according to MITRE ATT&CK.

Upgrading to version 3.5.32 or 3.6.13 eliminates this vulnerability.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Vendor

• etcd-io

Name

• etcd

Version

• 3.5.0
• 3.5.1
• 3.5.2
• 3.5.3
• 3.5.4
• 3.5.5
• 3.5.6
• 3.5.7
• 3.5.8
• 3.5.9
• 3.5.10
• 3.5.11
• 3.5.12
• 3.5.13
• 3.5.14
• 3.5.15
• 3.5.16
• 3.5.17
• 3.5.18
• 3.5.19
• 3.5.20
• 3.5.21
• 3.5.22
• 3.5.23
• 3.5.24
• 3.5.25
• 3.5.26
• 3.5.27
• 3.5.28
• 3.5.29
• 3.5.30
• 3.5.31
• 3.6.0
• 3.6.1
• 3.6.2
• 3.6.3
• 3.6.4
• 3.6.5
• 3.6.6
• 3.6.7
• 3.6.8
• 3.6.9
• 3.6.10
• 3.6.11
• 3.6.12

Website

• Product: https://github.com/etcd-io/etcd/

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