CVE-2026-53769: Avo missing upload authorization in AttachmentsController

CVE-2026-53769 · Severity: medium · CVSS 6.5 · Published 2026-09-04

Avo is an admin panel framework for Ruby on Rails applications. A vulnerability in its file upload system allows authenticated users to bypass security policies and upload or replace files on records they shouldn't be able to modify. This could allow a restricted user to overwrite important documents or images, potentially leading to data integrity issues or unauthorized content changes within the application.

Technologies: avo (RubyGems). Vendors: RubyGems.

Quick answers

Is CVE-2026-53769 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-53769 being exploited in the wild.
How severe is CVE-2026-53769?
Medium severity, with a CVSS score of 6.5, published 4 September 2026.
Which products and versions are affected?
avo (RubyGems) >= 2.28.0, < 3.32.0, ECOSYSTEM:introduced=2.28.0,fixed=3.32.0.
Is there a fix for CVE-2026-53769?
Yes. avo (RubyGems): upgrade to 3.32.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-53769 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-53769?
Check whether you run avo (RubyGems) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • avo (RubyGems): upgrade to 3.32.0 or later
    bundle update avo

Technical details

A missing authorization check exists in `Avo::AttachmentsController#create`. The endpoint processes file uploads and attaches them to records via ActiveStorage without invoking the expected Pundit-style policy methods like `upload_{FIELD_ID}?` or `update?`. An authenticated attacker can directly POST to the `/avo_api/resources/:resource_name/:id/attachments/` endpoint to modify attachments on a resolved record, even if their role is explicitly restricted by application policies. This bypasses both UI-level controls and server-side policy enforcement. The issue is fixed in version 3.32.0.

Affected products

  • avo-hq avo >= 2.28.0, < 3.32.0

Identifiers

  • CVE-2026-53769
  • GHSA-pqpw-cvm4-8mv9

Timeline

  • 2026-05-29: disclosed: Vulnerability confirmed via source inspection and PoC.
  • 2026-06-02: advisory: GitHub Advisory published.
  • 2026-07-09: patched: Advisory updated with final details.

References

This page as Markdown. Free to reuse under CC BY 4.0 with a link back.