CVE-2026-66003 frappe CVE debrief

Who should care

Defenders responsible for Frappe deployments should assess exposure and apply the vendor-provided patch to prevent unauthorized data access. This includes verifying the version of Frappe in use, reviewing system configurations, and ensuring that appropriate security measures are in place. Additionally, defenders should monitor for potential exploitation attempts and review system logs for signs of unauthorized access.

Why it matters

Defenders should prioritize verifying exposure and applying the vendor-provided patch to prevent unauthorized data access in Frappe deployments.

• Potential unauthorized data access through the REST API
• Need to verify exposure and apply the vendor-provided patch

Technical summary

The Frappe framework does not consistently enforce linked DocType permissions when records are retrieved through the REST API, allowing low-privileged authenticated users to obtain fields from linked records outside their permitted scope. This issue arises from a flawed permission check in the REST API, which fails to account for the permissions of linked DocTypes. As a result, attackers can exploit this vulnerability to access sensitive data. The vendor has addressed this issue in version 15.115.0 by enhancing permission checks.

Defensive priority

Defenders should prioritize verifying exposure and applying the vendor-provided patch.

Recommended defensive actions

• Verify if the system uses Frappe and assess exposure to the vulnerability
• Apply the vendor-provided patch to prevent unauthorized data access
• Monitor for potential exploitation attempts
• 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 NVD entry provide details on the access control bypass vulnerability in Frappe. Evidence is limited to public sources and may not be comprehensive. Defenders should verify exposure and apply the vendor-provided patch. The vulnerability affects Frappe deployments and allows low-privileged users to access unauthorized data through the REST API. Further verification is necessary to determine the full scope of affected systems and potential impact.

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.