CVE-2026-105820 HashiCorp CVE debrief

Who should care

Defenders and administrators of Vault Enterprise instances with namespace configurations should assess exposure and prioritize patching. Verify current version and upgrade to a fixed version if necessary. Monitor policy usage and token assignments for potential anomalies.

Why it matters

CVE-2026-105820 is a medium-severity vulnerability in Vault Enterprise's ACL policy cache that allows cross-namespace policy resolution. Defenders should prioritize patching affected instances, verify current versions, and monitor policy usage to prevent potential unauthorized access or privilege escalation.

• Potential unauthorized access to sensitive data or capabilities
• Possible escalation of privileges within Vault Enterprise
• Need for verification of current version and namespace configurations
• Priority on patching affected instances to prevent exploitation

Technical summary

The vulnerability in Vault Enterprise's ACL policy cache allows cross-namespace policy resolution when policy names contain path traversal constructs. This may enable a token with specially crafted policy names to use capabilities of policies in other namespaces, including the root namespace. The issue is fixed in Vault Enterprise versions 2.1.2, 1.21.12, 1.20.17, and 1.19.23. Defenders should prioritize patching affected instances, especially those with namespace configurations, and verify current versions to prevent potential unauthorized access or privilege escalation.

Defensive priority

Defenders should prioritize patching affected Vault Enterprise instances, especially those with namespace configurations. Verify the current version and upgrade to a fixed version if necessary. Monitor policy usage and token assignments for potential anomalies.

Recommended defensive actions

• Patch affected Vault Enterprise instances to versions 2.1.2, 1.21.12, 1.20.17, or 1.19.23.
• Verify current Vault Enterprise version and namespace configurations.
• Monitor policy usage and token assignments for anomalies.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record and source item provide details on the vulnerability, affected versions, and fixed versions. The NVD entry is currently empty. Defenders should verify current Vault Enterprise versions, review namespace configurations, and monitor policy usage for potential anomalies. Evidence is limited to CVE and source item details, with no additional information available for further verification.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.