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

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

Avo has a XSS vulnerability on `return_to` param

Technologies: avo (RubyGems). 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
    bundle update avo

Affected products

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

Identifiers

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

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