How severe is CVE-2022-23520?

CVE-2022-23520 has a CVSS score of 6.1/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2022-23520?

CVE-2022-23520 affects the following packages: rails-html-sanitizer (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2022-23520?

Update rails-html-sanitizer to 1.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-23520 is resolved across your whole dependency graph.

How do I detect CVE-2022-23520 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rails-html-sanitizer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2022-23520 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2022-23520?

O3 pinpoints whether CVE-2022-23520 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2022-23520 actively exploited in the wild?

Yes. There are 2 known exploit references for CVE-2022-23520, including 2 in-the-wild exploitations observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2022-23520?

CVE-2022-23520 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 62th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2022-23520 published, and has it been updated?

CVE-2022-23520 was published on December 14, 2022 and was last updated on April 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2022-23520: rails-html-sanitizer Cross-Site Scripting (Medi…

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk62th percentile+0.75%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

💎rails-html-sanitizer

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`rails-html-sanitizer`	all versions	1.4.4

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rails-html-sanitizer. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update rails-html-sanitizer to 1.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-23520 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2022-23520 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2022-23520. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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 "st

O3 Security · Impact-Aware SCA

Is CVE-2022-23520 in your dependencies?

O3 detects CVE-2022-23520 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2022-23520