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

Source: https://junglewise.ai/threats/cve-2026-53769-avo-missing-upload-authorization-in-attachmentscontroller  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-04. Updated: 2026-07-09  
License: CC BY 4.0 with a link back

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)](https://junglewise.ai/threats/technologies/avo). Vendors: [RubyGems](https://junglewise.ai/threats/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

  ```sh
  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

- [https://api.github.com/users/tarryGrain0](https://api.github.com/users/tarryGrain0)
- [https://github.com/tarryGrain0](https://github.com/tarryGrain0)
- [https://api.github.com/users/tarryGrain0/gists%7B/gist_id%7D](https://api.github.com/users/tarryGrain0/gists%7B/gist_id%7D)
- [https://api.github.com/users/tarryGrain0/repos](https://api.github.com/users/tarryGrain0/repos)
- [https://avatars.githubusercontent.com/u/77441982?v=4](https://avatars.githubusercontent.com/u/77441982?v=4)
- [https://api.github.com/users/tarryGrain0/events%7B/privacy%7D](https://api.github.com/users/tarryGrain0/events%7B/privacy%7D)

## Related threats

- [Avo missing authorization in association attach endpoint](https://junglewise.ai/threats/cve-2026-55518-avo-missing-authorization-in-association-attach-endpoint)
- [Avo broken access control in ActionsController](https://junglewise.ai/threats/cve-2026-42205-avo-broken-access-control-in-actionscontroller)
- [Avo has a XSS vulnerability on `return_to` param](https://junglewise.ai/threats/cve-2026-33209-avo-has-a-xss-vulnerability-on-return-to-param)
- [Cross-site scripting (XSS) in Action messages on Avo](https://junglewise.ai/threats/cve-2024-22411-cross-site-scripting-xss-in-action-messages-on-avo)
- [avo vulnerable to stored cross-site scripting (XSS) in key_value field](https://junglewise.ai/threats/cve-2024-22191-avo-vulnerable-to-stored-cross-site-scripting-xss-in-key-value)