# CVE-2026-33209: Avo has a XSS vulnerability on `return_to` param

Source: https://junglewise.ai/threats/cve-2026-33209-avo-has-a-xss-vulnerability-on-return-to-param  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-03-18  
License: CC BY 4.0 with a link back

CVE-2026-33209 · Severity: medium · CVSS 4 · Published 2026-03-18

Avo has a XSS vulnerability on `return_to` param

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

## Quick answers

**Is CVE-2026-33209 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-33209 being exploited in the wild.

**How severe is CVE-2026-33209?** Medium severity, with a CVSS score of 4, published 18 March 2026.

**Which products and versions are affected?** avo (RubyGems) ECOSYSTEM:introduced=0,fixed=3.30.3.

**Is there a fix for CVE-2026-33209?** Yes. avo (RubyGems): upgrade to 3.30.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-33209?** 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 3.30.3 or later

  ```sh
  bundle update avo
  ```


## Affected products

- avo (RubyGems) ECOSYSTEM:introduced=0,fixed=3.30.3

## Identifiers

- CVE-2026-33209
- GHSA-762r-27w2-q22j

## Related threats

- [Avo missing upload authorization in AttachmentsController](https://junglewise.ai/threats/cve-2026-53769-avo-missing-upload-authorization-in-attachmentscontroller)
- [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)
- [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)