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TI-2026-25749 Aliases CVE-2026-33343GHSA-rfx7-8w68-q57q

etcd: Nested etcd transactions bypass RBAC authorization checks

Priority LOW 34CWE-863Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-863.

Summary

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, an authenticated user with RBAC restricted permissions on key ranges can use nested transactions to bypass all key-level authorization. This allows any authenticated user with direct access to etcd to effectively ignore all key range restrictions, accessing the entire etcd data store. 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 require strong client identity at the transport layer, such as mTLS with tightly scoped client certificate distribution.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00219 12th percentileScored 2026-11-07
Fix Partial etcd (etcd-io): 3.5.28, 3.6.9, 3.4.42go.etcd.io/etcd/v3 (Go): 3.6.9, 3.5.28, 3.4.42Red Hat: 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
etcd-ioetcd3.5.0-alpha.0 to before 3.5.28; 3.6.0-alpha.0 to before 3.6.9; before 3.4.423.5.28, 3.6.9, 3.4.42Patch availableCNA
—go.etcd.io/etcd/v3 (Go)3.6.0-alpha.0 to before 3.6.93.6.9Patch availableGHSA-rfx7-8w68-q57q
—go.etcd.io/etcd/v3 (Go)3.5.0-alpha.0 to before 3.5.283.5.28Patch availableGHSA-rfx7-8w68-q57q
—go.etcd.io/etcd/v3 (Go)before 3.4.423.4.42Patch availableGHSA-rfx7-8w68-q57q
—go.etcd.io/etcd (Go)up to 3.3.27—No fix listedGHSA-rfx7-8w68-q57q
  • etcd Vendoretcd-io Affected 3.5.0-alpha.0 to before 3.5.28; 3.6.0-alpha.0 to before 3.6.9; before 3.4.42 Fixed in 3.5.28, 3.6.9, 3.4.42 Patch available CNA
  • go.etcd.io/etcd/v3 (Go) Vendor— Affected 3.6.0-alpha.0 to before 3.6.9 Fixed in 3.6.9 Patch available GHSA-rfx7-8w68-q57q
  • go.etcd.io/etcd/v3 (Go) Vendor— Affected 3.5.0-alpha.0 to before 3.5.28 Fixed in 3.5.28 Patch available GHSA-rfx7-8w68-q57q
  • go.etcd.io/etcd/v3 (Go) Vendor— Affected before 3.4.42 Fixed in 3.4.42 Patch available GHSA-rfx7-8w68-q57q
  • go.etcd.io/etcd (Go) Vendor— Affected up to 3.3.27 Fixed in — No fix listed GHSA-rfx7-8w68-q57q

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:*before 3.4.42; 3.5.0 to before 3.5.28; 3.6.0 to before 3.6.9Vulnerableetcd-io
  • cpe:2.3:a:etcd:etcd:*:*:*:*:*:*:*:* Versions before 3.4.42; 3.5.0 to before 3.5.28; 3.6.0 to before 3.6.9 Vulnerable ·etcd-io

Remediation

  • Fix · CNA etcd (etcd-io) Fixed in 3.5.28, 3.6.9, 3.4.42
  • Fix · GHSA-rfx7-8w68-q57q go.etcd.io/etcd/v3 (Go) Fixed in 3.6.9 Advisory →
  • Fix · GHSA-rfx7-8w68-q57q go.etcd.io/etcd/v3 (Go) Fixed in 3.5.28 Advisory →
  • Fix · GHSA-rfx7-8w68-q57q go.etcd.io/etcd/v3 (Go) Fixed in 3.4.42 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenStack Platform 16.2AffectedNo fix yet: Fix deferred
Red Hat OpenStack Platform 17.1AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-33343
  2. 2026-10-03 Alias added: GHSA-rfx7-8w68-q57q

References

Advisory 2

Other 1

  • TI-2021-09444 Authentication vulnerability found in Etcd-io v.3.4.10 allows remote attackers to… CVSS 3.1CRITICAL 9.8
  • TI-2026-25810 etcd: Authorization bypasses in multiple APIs CVSS 4.0HIGH 8.8
  • TI-2022-15016 Etcd v3.5.4 allows remote attackers to cause a denial of service via function… CVSS 3.1HIGH 7.5
  • TI-2018-12096 Improper authentication in etcd: CVSS 3.1HIGH 8.1
  • TI-2026-42635 etcd: gRPC client listener does not enforce `--client-crl-file` certificate revocation CVSS 3.1HIGH 8.1
  • TI-2020-11888 Improper Preservation of Permissions in etcd CVSS 3.1HIGH 7.1
See all 10 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences