CVE-2026-66002Network attack vector

User enumeration via distinguishable PDDR responses

Published Aug 20, 2026 · Updated Aug 21, 2026

Observable response discrepancy in Frappe Framework before 15.115.0 and 16.27.0 allows remote attackers to enumerate registered users. The public request-data web form serializes user_name for registered addresses and persists their PersonalDataDownloadRequest records, while unregistered addresses produce a different response shape and no stored record. No authentication or user interaction is required; disclosure is limited to whether submitted email addresses belong to registered accounts.

CVSS severity6.9
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Observable response discrepancy in Frappe Framework before 15.115.0 and 16.27.0 allows remote attackers to enumerate registered users. The public request-data web form serializes user_name for registered addresses and persists their PersonalDataDownloadRequest records, while unregistered addresses produce a different response shape and no stored record. No authentication or user interaction is required; disclosure is limited to whether submitted email addresses belong to registered accounts.

The record

CVE
CVE-2026-66002
Published
Aug 20, 2026
Updated
Aug 21, 2026
Vendor
Frappe Technologies Pvt. Ltd.
Product
Frappe Framework
Classifications
CWE-204, T1087
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 15.115.0
  2. Affected versionversion=>= 16.0.0-beta.1, < 16.27.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Frappe Technologies Pvt. Ltd. · Frappe Frameworkversion=< 15.115.0; version=>= 16.0.0-beta.1, < 16.27.0

Published CVSS scores

6.9GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-204Observable Response Discrepancy
T1087Account Discovery

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo