etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42, 3.5.28, and 3.6.9, unauthorized users may bypass authentication or authorization checks and call certain etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch, audit, and recovery workflows. Kubernetes does not rely on etcd’s built-in authentication and authorization. Instead, the API server handles authentication and authorization itself, so typical Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice. Restrict network access to etcd server ports so only trusted components can connect and/or require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.

The remote Redhat Enterprise Linux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:28047 advisory.

    etcd is a highly-available key value store for shared configuration.

    Security Fix(es):

    * net/url: Memory exhaustion in query parameter parsing in net/url     (CVE-2025-61726)

    * golang: Denial of Service due to excessive resource consumption via     crafted certificate (CVE-2025-61729)

    * Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679)

    * Incorrect enforcement of email constraints in crypto/x509     (CVE-2026-27137)

    * crypto/tls: golang: Go: Denial of Service vulnerability in certificate     chain building (CVE-2026-32280)

    * golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update     messages (CVE-2026-32283)

    * google.golang.org/grpc/authz: gRPC-Go: Authorization bypass due to     improper HTTP/2 path validation (CVE-2026-33186)

    * golang: Go crypto/x509: Certificate validation bypass due to incorrect     DNS constraint application (CVE-2026-33810)

    * crypto/tls: Incorrect certificate validation during TLS session     resumption (CVE-2025-68121)

    * internal/syscall/unix: Root.Chmod can follow symlinks out of the root     (CVE-2026-32282)

    * etcd: Authorization bypass allows information disclosure and denial of     service (CVE-2026-33413)

    For more details about the security issue(s), including the impact, a CVSS     score, acknowledgments, and other related information, refer to the CVE     page listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

An update of the etcd package has been released.

The version of CBL-Mariner Releases installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2026-33413 advisory.

  - etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42,     3.5.28, and 3.6.9, unauthorized users May bypass authentication or authorization checks and call certain     etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In     unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn     cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for     operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease     ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch,     audit, and recovery workflows. Kubernetes does not rely on etcd's built-in authentication and     authorization. Instead, the API server handles authentication and authorization itself, so typical     Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading     is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice.
    Restrict network access to etcd server ports so only trusted components can connect and/or require strong     client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.
    (CVE-2026-33413)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The version of CBL-Mariner Releases installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2026-33413 advisory.

  - etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42,     3.5.28, and 3.6.9, unauthorized users May bypass authentication or authorization checks and call certain     etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In     unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn     cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for     operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease     ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch,     audit, and recovery workflows. Kubernetes does not rely on etcd's built-in authentication and     authorization. Instead, the API server handles authentication and authorization itself, so typical     Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading     is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice.
    Restrict network access to etcd server ports so only trusted components can connect and/or require strong     client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.
    (CVE-2026-33413)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42,     3.5.28, and 3.6.9, unauthorized users may bypass authentication or authorization checks and call certain     etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In     unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn     cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for     operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease     ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch,     audit, and recovery workflows. Kubernetes does not rely on etcd's built-in authentication and     authorization. Instead, the API server handles authentication and authorization itself, so typical     Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading     is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice.
    Restrict network access to etcd server ports so only trusted components can connect and/or require strong     client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.
    (CVE-2026-33413)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - etcd is a distributed key-value store for the data of a distributed system. Prior to versions 3.4.42,
    3.5.28, and 3.6.9, unauthorized users may bypass authentication or authorization checks and call certain
    etcd functions in clusters that expose the gRPC API to untrusted or partially trusted clients. In
    unpatched etcd clusters with etcd auth enabled, unauthorized users are able to call MemberList and learn
    cluster topology, including member IDs and advertised endpoints; call Alarm, which can be abused for
    operational disruption or denial of service; use Lease APIs, interfering with TTL-based keys and lease
    ownership; and/or trigger compaction, permanently removing historical revisions and disrupting watch,
    audit, and recovery workflows. Kubernetes does not rely on etcd’s built-in authentication and
    authorization. Instead, the API server handles authentication and authorization itself, so typical
    Kubernetes deployments are not affected. Versions 3.4.42, 3.5.28, and 3.6.9 contain a patch. If upgrading
    is not immediately possible, reduce exposure by treating the affected RPCs as unauthenticated in practice.
    Restrict network access to etcd server ports so only trusted components can connect and/or require strong
    client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.
    (CVE-2026-33413)

ID	Name	Product	Family	Severity
322151	RHEL 9 : Red Hat OpenStack Platform 17.1 (etcd) (RHSA-2026:28047)	Nessus	Red Hat Local Security Checks	high
313510	Photon OS 4.0: Etcd PHSA-2026-4.0-1012	Nessus	PhotonOS Local Security Checks	high
306492	Photon OS 5.0: Etcd PHSA-2026-5.0-0802	Nessus	PhotonOS Local Security Checks	high
304498	CBL Mariner 2.0 Security Update: CBL-Mariner Releases (CVE-2026-33413)	Nessus	MarinerOS Local Security Checks	high
304372	Azure Linux 3.0 Security Update: CBL-Mariner Releases (CVE-2026-33413)	Nessus	Azure Linux Local Security Checks	high
303898	Linux Distros Unpatched Vulnerability : CVE-2026-33413	Nessus	Misc.	high
439092	SCA: security update for go.etcd.io/etcd/v3 (GHSA-q8m4-xhhv-38mg)	Tenable Cloud Security	SCA Checks	high
439092	SCA: security update for go.etcd.io/etcd/v3 (GHSA-q8m4-xhhv-38mg)	Tenable Self-Hosted Container Security	SCA Checks	high

Detections

Analytics

CVE-2026-33413

high

Tenable Plugins

high

high

high

high

high

high

high

high