Rails has a possible XSS vulnerability in its Action View tag helpers

BASSO 2.3CVE-2026-33168 · GHSA-v55j-83pf-r9cq · Published 23/03/2026 · updated 17/06/2026

Package	Affected versions	Patched versions
actionview RubyGems	`≥ 8.0.0.beta1, < 8.0.4.1≥ 8.1.0.beta1, < 8.1.2.1< 7.2.3.1`	`8.0.4.18.1.2.17.2.3.1`

Description

Impact

When a blank string is used as an HTML attribute name in Action View tag helpers, the attribute escaping is bypassed, producing malformed HTML. A carefully crafted attribute value could then be misinterpreted by the browser as a separate attribute name, possibly leading to XSS. Applications that allow users to specify custom HTML attributes are affected.

Releases

The fixed releases are available at the normal locations.

Credit

This issue was responsibly reported by Hackerone researcher taise.

NVD description

Action View provides conventions and helpers for building web pages with the Rails framework. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, when a blank string is used as an HTML attribute name in Action View tag helpers, the attribute escaping is bypassed, producing malformed HTML. A carefully crafted attribute value could then be misinterpreted by the browser as a separate attribute name, possibly leading to XSS. Applications that allow users to specify custom HTML attributes are affected. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

References

rails/rails security advisory · WEB
nvd.nist.gov/vuln/detail/CVE-2026-33168 · ADVISORY
rails/rails commit 0b6f800 · WEB
rails/rails commit 63f5ad8 · WEB
rails/rails commit c79a07d · WEB
rails/rails · PACKAGE
rails/rails release v7.2.3.1 · WEB
rails/rails release v8.0.4.1 · WEB
rails/rails release v8.1.2.1 · WEB
rubysec/ruby-advisory-db · WEB

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Package

Affected versions

Patched versions

actionview

RubyGems

≥ 8.0.0.beta1, < 8.0.4.1≥ 8.1.0.beta1, < 8.1.2.1< 7.2.3.1