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No exploitation reportedFix available

CVE-2026-33413

No exploitation reported by the sources we read.

  • Published2026-03-26
  • WeaknessCWE-862

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2026-03-2614:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-33413?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-33413?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV · NVD
go.etcd.io/etcd
BranchAffectedFixed in
3.3≤ 3.3.27no fix published
Etcd
BranchAffectedFixed in
3.6≥ 3.6.0, < 3.6.93.6.9
3.6≥ 3.6.0-alpha.0, < 3.6.93.6.9
3.5≥ 3.5.0, < 3.5.283.5.28
3.5≥ 3.5.0-alpha.0, < 3.5.283.5.28
3.4< 3.4.423.4.42

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

  • RHSA-2026:28047 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Red Hat OpenStack Platform 17.1 (etcd) security update

  • RHSA-2026:23345 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Multicluster Global Hub 1.6.2 security update

  • RHSA-2026:22347 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Multicluster Global Hub 1.4.5 security update

  • RHSA-2026:21769 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: Multicluster Global Hub 1.5.4 security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2026:28047 · 4 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  2. Vendor fix Red Hat Product Security RHSA-2026:23345 · 4 productsFor more details, see the Red Hat Advanced Cluster Management for Kubernetes documentation: https://docs.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.15/html/multicluster_global_hub/index
  3. Vendor fix Red Hat Product Security RHSA-2026:22347 · 4 productsFor more details, see the Red Hat Advanced Cluster Management for Kubernetes documentation: https://docs.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.13/html/multicluster_global_hub/index
  4. Vendor fix Red Hat Product Security RHSA-2026:21769 · 4 productsFor more details, see the Red Hat Advanced Cluster Management for Kubernetes documentation: https://docs.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes/2.14/html/multicluster_global_hub/index
  5. Workaround from the vendor Red Hat Product Security RHSA-2026:28047 · 4 productsRestrict network access to etcd server ports to ensure only trusted components can establish connections. Implement strong client identity at the transport layer, such as mTLS, with tightly scoped client certificate distribution. This will limit unauthorized access to etcd functions.

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2026-03-26
  • OpenCVESSVC decisionnone—
  • CNACVSS 4.08.8read 2026-10-23
  • NVDCVSS 3.18.8read 2026-10-23
  • CNAweakness (CWE)CWE-862read 2026-10-23
  • FIRST EPSSEPSS score0.3 %2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0 vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Published
2026-03-26
Last Modified
2026-06-17
NVD status
Analyzed

Frequently asked questions

What is CVE-2026-33413?

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.

Is CVE-2026-33413 actively exploited?

Active exploitation of CVE-2026-33413 has not been confirmed. Its EPSS score was 0.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-33413?

CVE-2026-33413 has a CVSS v3 base score of 8.8 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

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