How severe is GHSA-mcvf-2q2m-x72m?

GHSA-mcvf-2q2m-x72m 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 GHSA-mcvf-2q2m-x72m?

GHSA-mcvf-2q2m-x72m affects the following packages: rails-html-sanitizer (RubyGems). Ecosystems affected: RubyGems.

How do I fix GHSA-mcvf-2q2m-x72m?

Update rails-html-sanitizer to 1.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mcvf-2q2m-x72m is resolved across your whole dependency graph.

How do I detect GHSA-mcvf-2q2m-x72m 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 GHSA-mcvf-2q2m-x72m 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-mcvf-2q2m-x72m?

O3 pinpoints whether GHSA-mcvf-2q2m-x72m 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 GHSA-mcvf-2q2m-x72m actively exploited in the wild?

Yes. There are 1 known exploit references for GHSA-mcvf-2q2m-x72m, including 1 in-the-wild exploitation 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 GHSA-mcvf-2q2m-x72m?

GHSA-mcvf-2q2m-x72m has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 54th 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-mcvf-2q2m-x72m?

GHSA-mcvf-2q2m-x72m 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-mcvf-2q2m-x72m published, and has it been updated?

GHSA-mcvf-2q2m-x72m was published on December 13, 2022 and was last updated on November 4, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎 RubyGems

GHSA-mcvf-2q2m-x72m

MEDIUM

Improper neutralization of data URIs may allow XSS in rails-html-sanitizer

Also known asCVE-2022-23518

Published

Dec 13, 2022

Updated

Nov 4, 2025

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk54th percentile+0.56%

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

Summary

rails-html-sanitizer >= 1.0.3, < 1.4.4 is vulnerable to cross-site scripting via data URIs when used in combination with Loofah >= 2.1.0.

Mitigation

Upgrade to rails-html-sanitizer >= 1.4.4.

Severity

The maintainers have evaluated this as Medium Severity 6.1.

References

Credit

This vulnerability was independently reported by Maciej Piechota (@haqpl) and Mrinmoy Das (@goromlagche).

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`rails-html-sanitizer`	≥ 1.0.3&&< 1.4.4	1.4.4

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

rails-html-sanitizer is responsible for sanitizing HTML fragments in Rai…

github.comNVDDec 2022

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 GHSA-mcvf-2q2m-x72m 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 GHSA-mcvf-2q2m-x72m 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 GHSA-mcvf-2q2m-x72m. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

## Summary rails-html-sanitizer `>= 1.0.3, < 1.4.4` is vulnerable to cross-site scripting via data URIs when used in combination with Loofah `>= 2.1.0`. ## Mitigation Upgrade to rails-html-sanitizer `>= 1.4.4`. ## Severity The maintainers have evaluated this as [Medium Severity 6.1](https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N). ## References - [CWE - CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (4.9)](https://cwe.mitre.org/data/definitions/79.html) - [SVG MIME Type (image/svg+xml) is misleading

O3 Security · Impact-Aware SCA

Is GHSA-mcvf-2q2m-x72m in your dependencies?

O3 detects GHSA-mcvf-2q2m-x72m 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