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TI-2026-27206 Aliases CVE-2026-34984GHSA-r2pg-r6h7-crf3

External Secrets Operator has DNS exfiltration via getHostByName in its v2 template engine

Priority LOW 31CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-200.

Summary

External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Versions 2.2.0 and below contain a vulnerability in runtime/template/v2/template.go where the v2 template engine removes env and expandenv from Sprig's TxtFuncMap() but leaves the getHostByName function accessible to user-controlled templates. Since ESO executes templates within the controller process, an attacker who can create or update templated ExternalSecret resources can invoke controller-side DNS lookups using secret-derived values. This creates a DNS exfiltration primitive, allowing fetched secret material to be leaked via DNS queries without requiring direct outbound network access from the attacker's workload. The impact is a confidentiality issue, particularly in environments where untrusted or lower-trust users can author templated ExternalSecret resources and the controller has DNS resolution capability. This issue has been fixed in version 2.3.0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00262 18th percentileScored 2026-11-07
Fix Partial external-secrets (external-secrets): 2.3.0github.com/external-secrets/external-secrets (Go): 1.3.3-0.20260331202714-6800989bdc12Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
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
external-secretsexternal-secretsbefore 2.3.02.3.0Patch availableCNA
—github.com/external-secrets/external-secrets (Go)before 1.3.3-0.20260331202714-6800989bdc121.3.3-0.20260331202714-6800989bdc12Patch availableGHSA-r2pg-r6h7-crf3
—github.com/external-secrets/external-secrets (Go)2.0.0 – 2.2.0—No fix listedGHSA-r2pg-r6h7-crf3
  • external-secrets Vendorexternal-secrets Affected before 2.3.0 Fixed in 2.3.0 Patch available CNA
  • github.com/external-secrets/external-secrets (Go) Vendor— Affected before 1.3.3-0.20260331202714-6800989bdc12 Fixed in 1.3.3-0.20260331202714-6800989bdc12 Patch available GHSA-r2pg-r6h7-crf3
  • github.com/external-secrets/external-secrets (Go) Vendor— Affected 2.0.0 – 2.2.0 Fixed in — No fix listed GHSA-r2pg-r6h7-crf3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:external-secrets:external_secrets_operator:*:*:*:*:*:*:*:*before 2.3.0Vulnerableexternal-secrets
  • cpe:2.3:a:external-secrets:external_secrets_operator:*:*:*:*:*:*:*:* Versions before 2.3.0 Vulnerable ·external-secrets

Remediation

  • Fix · CNA external-secrets (external-secrets) Fixed in 2.3.0
  • Fix · GHSA-r2pg-r6h7-crf3 github.com/external-secrets/external-secrets (Go) Fixed in 1.3.3-0.20260331202714-6800989bdc12 Advisory →

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
External Secrets Operator for Red Hat OpenShiftAffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34984
  2. 2026-10-03 Alias added: GHSA-r2pg-r6h7-crf3

References

Patch 1

Advisory 2

Other 2

  • TI-2024-30153 External Secrets Operator vulnerable to privilege escalation CVSS 3.1HIGH 8.8
  • TI-2024-24309 Insecure permissions in external-secrets v0.9.16 allows attackers to access sensitive… CVSS 3.1CRITICAL 9.8
  • TI-2026-18338 External Secrets Operator insecurely retrieves secrets through the getSecretKey templating function CVSS 4.0CRITICAL 9.3

Sources

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