How severe is GHSA-638j-pmjw-jq48?

No CVSS score has been assigned to GHSA-638j-pmjw-jq48 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-638j-pmjw-jq48?

GHSA-638j-pmjw-jq48 affects the following packages: rails-html-sanitizer (RubyGems). Ecosystems affected: RubyGems.

How do I fix GHSA-638j-pmjw-jq48?

Update rails-html-sanitizer to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-638j-pmjw-jq48 is resolved across your whole dependency graph.

How do I detect GHSA-638j-pmjw-jq48 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rails-html-sanitizer, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-638j-pmjw-jq48 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 GHSA-638j-pmjw-jq48?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-638j-pmjw-jq48 can be triaged on real exposure rather than presence alone.

Is GHSA-638j-pmjw-jq48 actively exploited in the wild?

No public exploit code has been indexed for GHSA-638j-pmjw-jq48 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-638j-pmjw-jq48?

GHSA-638j-pmjw-jq48 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 40th 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.

What type of vulnerability is GHSA-638j-pmjw-jq48?

GHSA-638j-pmjw-jq48 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-638j-pmjw-jq48 published, and has it been updated?

GHSA-638j-pmjw-jq48 was published on December 2, 2024 and was last updated on December 3, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎 RubyGems

Not in CISA KEV

GHSA-638j-pmjw-jq48 — rails-html-sanitizer

Fix: rails/rails-html-sanitizer@f02ffbb

GHSA-638j-pmjw-jq48 is a Cross-site Scripting (XSS) vulnerability in rails-html-sanitizer. A fix is available for rails-html-sanitizer — see the affected versions and patch details below.

rails-html-sanitizer has XSS vulnerability with certain configurations

Also known asCVE-2024-53986

Published

Dec 2, 2024

Updated

Dec 3, 2024

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-638j-pmjw-jq48.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs40th percentile — riskier than 40% of all scored CVEsHighest risk

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.

Real-World Exposure

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

Summary

There is a possible XSS vulnerability with certain configurations of Rails::HTML::Sanitizer 1.6.0 when used with Rails >= 7.1.0.

Versions affected: 1.6.0
Not affected: < 1.6.0
Fixed versions: 1.6.1

Impact

A possible XSS vulnerability with certain configurations of Rails::HTML::Sanitizer may allow an attacker to inject content if HTML5 sanitization is enabled and the application developer has overridden the sanitizer's allowed tags in the following way:

the "math" and "style" elements are both explicitly allowed

Code is only impacted if Rails is configured to use HTML5 sanitization, please see documentation for config.action_view.sanitizer_vendor and config.action_text.sanitizer_vendor for more information on these configuration options.

The default configuration is to disallow these elements. Code is only impacted if allowed tags are being overridden. Applications may be doing this in a few different ways:

using application configuration to configure Action View sanitizers' allowed tags:

# In config/application.rb
config.action_view.sanitized_allowed_tags = ["math", "style"]

see https://guides.rubyonrails.org/configuring.html#configuring-action-view

using a :tags option to the Action View helper sanitize:

<%= sanitize @comment.body, tags: ["math", "style"] %>

see https://api.rubyonrails.org/classes/ActionView/Helpers/SanitizeHelper.html#method-i-sanitize

setting Rails::HTML5::SafeListSanitizer class attribute allowed_tags:

# class-level option
Rails::HTML5::SafeListSanitizer.allowed_tags = ["math", "style"]

(note that this class may also be referenced as Rails::Html::SafeListSanitizer)

using a :tags options to the Rails::HTML5::SafeListSanitizer instance method sanitize:

# instance-level option
Rails::HTML5::SafeListSanitizer.new.sanitize(@article.body, tags: ["math", "style"])

(note that this class may also be referenced as Rails::Html::SafeListSanitizer)

setting ActionText::ContentHelper module attribute allowed_tags:

ActionText::ContentHelper.allowed_tags = ["math", "style"]

All users overriding the allowed tags by any of the above mechanisms to include both "math" and "style" should either upgrade or use one of the workarounds.

Workarounds

Any one of the following actions will work around this issue:

Remove "math" or "style" from the overridden allowed tags,
Or, downgrade sanitization to HTML4 (see documentation for config.action_view.sanitizer_vendor and config.action_text.sanitizer_vendor for more information).

References

Credit

This vulnerability was responsibly reported by So Sakaguchi (mokusou) and taise.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`rails-html-sanitizer`	≥ 1.6.0&&< 1.6.1	1.6.1`bundle update rails-html-sanitizer --conservative`

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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rails-html-sanitizer to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-638j-pmjw-jq48 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-638j-pmjw-jq48 can be triaged on real exposure rather than presence alone.

Tailored to GHSA-638j-pmjw-jq48. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary There is a possible XSS vulnerability with certain configurations of Rails::HTML::Sanitizer 1.6.0 when used with Rails >= 7.1.0. * Versions affected: 1.6.0 * Not affected: < 1.6.0 * Fixed versions: 1.6.1 ## Impact A possible XSS vulnerability with certain configurations of Rails::HTML::Sanitizer may allow an attacker to inject content if HTML5 sanitization is enabled and the application developer has overridden the sanitizer's allowed tags in the following way: - the "math" and "style" elements are both explicitly allowed Code is only impacted if Rails is configured to use HTM

O3 Security · Impact-Aware SCA

Is GHSA-638j-pmjw-jq48 in your dependencies?

O3 Security finds GHSA-638j-pmjw-jq48 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works

GHSA-638j-pmjw-jq48 — rails-html-sanitizer

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

Real-World Exposure

Description

Summary

Impact

Workarounds

References

Credit

Affected Packages

Detection & mitigation playbook

Detect

Fix

Workarounds

How O3 protects you

Frequently Asked Questions

Is GHSA-638j-pmjw-jq48 in your dependencies?