GHSA-486f-hjj9-9vhh is a high-severity (CVSS 7.5) CWE-1333 vulnerability in loofah. A fix is available for loofah — see the affected versions and patch details below.
Inefficient Regular Expression Complexity in Loofah
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for GHSA-486f-hjj9-9vhh.
EPSS Exploitation Probability
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.
How urgent is this, really
GHSA-486f-hjj9-9vhh plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
loofahReal-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
Loofah < 2.19.1 contains an inefficient regular expression that is susceptible to excessive backtracking when attempting to sanitize certain SVG attributes. This may lead to a denial of service through CPU resource consumption.
Mitigation
Upgrade to Loofah >= 2.19.1.
Severity
The Loofah maintainers have evaluated this as High Severity 7.5 (CVSS3.1).
References
- CWE - CWE-1333: Inefficient Regular Expression Complexity (4.9)
- https://hackerone.com/reports/1684163
Credit
This vulnerability was responsibly reported by @ooooooo-q (https://github.com/ooooooo-q).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | loofah | all versions | 2.19.1bundle update loofah --conservative |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for loofah, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update loofah to 2.19.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-486f-hjj9-9vhh 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-486f-hjj9-9vhh can be triaged on real exposure rather than presence alone.
Tailored to GHSA-486f-hjj9-9vhh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Satellite 6.13 for RHEL 8 | satellite:el8/rubygem-loofah-0:2.19.1-1.el8sat | RHSA-2023:2097 |
Frequently Asked Questions
Is GHSA-486f-hjj9-9vhh in your dependencies?
O3 Security finds GHSA-486f-hjj9-9vhh across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.