CVE-2022-23520 rails-html-sanitizer contains an incomplete fix for an XSS vulnerability

What is CVE-2022-23520?

CVE-2022-23520 is a medium-severity cross-site scripting vulnerability in Debian Debian Linux, published on 14 Dec 2022. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

rails-html-sanitizer is responsible for sanitizing HTML fragments in Rails applications. Prior to version 1.4.4, there is a possible XSS vulnerability with certain configurations of Rails::Html::Sanitizer due to an incomplete fix of CVE-2022-32209. Rails::Html::Sanitizer may allow an attacker to inject content if the application developer has overridden the sanitizer's allowed tags to allow both "select" and "style" elements. Code is only impacted if allowed tags are being overridden. This issue is patched in version 1.4.4. All users overriding the allowed tags to include both "select" and "style" should either upgrade or use this workaround: Remove either "select" or "style" from the overridden allowed tags. NOTE: Code is _not_ impacted if allowed tags are overridden using either the :tags option to the Action View helper method sanitize or the :tags option to the instance method SafeListSanitizer#sanitize.

Weakness: CWE-79

Which versions are affected by CVE-2022-23520?

2 open source packages ship an affected version, including rails-html-sanitizer. It affects 2 products.

Products include Debian Debian Linux, Rubyonrails Rails Html Sanitizers.

How do I fix CVE-2022-23520?

Upgrade rails-html-sanitizer to 1.4.4 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2022-23520 being exploited?

There is no known exploitation of CVE-2022-23520 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-23520, GHSA-rrfc-7g8p-99q8, UBUNTU-CVE-2022-23520.