CVE-2022-23517 is a high-severity (CVSS 7.5) CWE-1333 vulnerability in rails-html-sanitizer. A fix is available for rails-html-sanitizer — see the affected versions and patch details below.
Inefficient Regular Expression Complexity in rails-html-sanitizer
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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 CVE-2022-23517.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
rails-html-sanitizerReal-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
Certain configurations of rails-html-sanitizer < 1.4.4 use 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 rails-html-sanitizer >= 1.4.4.
Severity
The 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 | rails-html-sanitizer | all versions | 1.4.4bundle update rails-html-sanitizer --conservative |
Affected Products
debian linuxdebianrails html sanitizersrubyonrailsDetection & mitigation playbook
Open-source dependencyDetect
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 1.4.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-23517 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
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-rails-html-sanitizer-0:1.4.4-1.el8sat | RHSA-2023:2097 |
Frequently Asked Questions
Is CVE-2022-23517 in your dependencies?
Find it across RubyGems, including transitive dependencies.