CVE-2026-53769
Received Received - Intake

Unauthorized File Upload in Avo Ruby on Rails Admin Framework

Vulnerability report for CVE-2026-53769, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-09-04

Last updated on: 2026-09-04

Assigner: GitHub, Inc.

Description

Avo is a framework to create admin panels for Ruby on Rails apps. From version 2.28.0 to before version 3.32.0, Avo's direct attachment upload endpoint lacks server-side upload authorization and bypasses the documented field-level upload policy methods such as upload_{FIELD_ID}?. An authenticated Avo user who can reach the Avo attachment upload endpoint can replace or add attachment content, including binary content, filename, and content-type metadata, on a resolved record even when both update? and upload_<field>? policies deny the operation. This primarily affects multi-role Avo Pro/Advanced-style deployments where non-administrator or restricted operator users can reach Avo and per-record or per-field operations are expected to be enforced by policies. This issue has been patched in version 3.32.0.

CVSS Scores

EPSS Scores

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Meta Information

Published
2026-09-04
Last Modified
2026-09-04
Generated
2026-09-05
AI Q&A
2026-09-05
EPSS Evaluated
N/A
NVD

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
avohq avo From 2.28.0 (inc) to 3.32.0 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-863 The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack-Flow Graph

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Executive Summary

Avo framework versions 2.28.0 to 3.32.0 have an issue where the direct attachment upload endpoint does not enforce server-side authorization. Authenticated users can modify or add attachments on records even when policy methods like upload_FIELD_ID? or update? deny the operation. This affects multi-role deployments where non-admin users can access Avo.

Detection Guidance

Check Avo version with bundle show avo or gem list avo. If version is between 2.28.0 and 3.32.0, the system is vulnerable. Inspect network traffic for unauthorized attachment uploads to /avo/attachments endpoint.

Impact Analysis

An attacker with access to the Avo upload endpoint could replace or add malicious attachments to records, potentially altering data integrity. This could lead to unauthorized changes in application content, affecting business operations or user trust.

Compliance Impact

This vulnerability could violate compliance requirements that mandate strict access controls and data integrity, such as GDPR's data protection principles or HIPAA's security rules. Unauthorized modifications to records may lead to non-compliance and potential legal consequences.

Mitigation Strategies

Upgrade Avo to version 3.32.0 or later immediately. Review and enforce upload policies for all roles. Restrict access to Avo admin panel endpoints for non-administrator users.

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