Vulnerability · Published Mar 20, 2026 · Assigned by GitHub_M

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

Medium 5.3

In plain English

A medium-severity cross-site scripting in avo from avo-hq. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.3Medium

Exploit odds (30 days)0.3%top 80.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Avo is a framework to create admin panels for Ruby on Rails apps. Prior to version 3.30.3, a reflected cross-site scripting (XSS) vulnerability exists in the return_to query parameter used in the avo interface. An attacker can craft a malicious URL that injects arbitrary JavaScript, which is executed when he clicks a dynamically generated navigation button. This issue has been patched in version 3.30.3.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
RubyGems	avo	3.30.3	GHSA-762r-27w2-q22j

Affected products (as reported)

Vendor	Product	Versions
avo-hq	avo	< 3.30.3

Weakness: CWE-79 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

References

https://github.com/avo-hq/avo/security/advisories/GHSA-762r-27w2-q22j x_refsource_CONFIRM
https://github.com/avo-hq/avo/pull/4330 x_refsource_MISC
https://github.com/avo-hq/avo/commit/4453d39ddc6309f3bc8ada73ef21e1971112de7d x_refsource_MISC
https://github.com/avo-hq/avo/releases/tag/v3.30.3 x_refsource_MISC