CVE-2026-44587
MediumCVSS 4.7Exploitation Probability (EPSS)
Low risk28th percentile — higher than 28% of all known CVEs
Summary
In the CarrierWave framework, versions prior to 2.2.7 and 3.1.3, the content_type_denylist check fails to properly handle regex metacharacters in string entries, leading to intended content types not being blocked. As a result, applications may be vulnerable to XSS attacks through uploading SVG files containing malicious JavaScript.
Risk Assessment
Organizations using CarrierWave may be exposed to XSS attacks, potentially leading to user data theft or session hijacking. The lack of proper protection against malicious SVG files poses a serious security threat to applications.
Recommendation
It is recommended to update the CarrierWave framework to versions 2.2.7 or 3.1.3 to fix the issue with the content_type_denylist. Additionally, conducting an audit of the application to identify and mitigate potential security vulnerabilities related to SVG file handling is advisable.
Original NVD description (English source)
CarrierWave is a framework to upload files from Ruby applications. In versions prior to 2.2.7 and 3.1.3, the content_type_denylist check fails to escape regex metacharacters in string entries, causing the denylist to silently not match the content types it is intended to block. In lib/carrierwave/uploader/content_type_denylist.rb:57, denylist entries are interpolated directly into a regex without Regexp.quote or anchoring, so an entry such as image/svg+xml becomes the pattern /image\/svg+xml/, in which + is treated as a quantifier rather than a literal character and therefore never matches the real MIME type image/svg+xml. This is inconsistent with the allowlist implementation, which correctly applies both Regexp.quote and a \A anchor. Other content types containing regex metacharacters, such as application/xhtml+xml, are affected as well. As a result, any application that relies on content_type_denylist to block image/svg+xml, most commonly to prevent stored XSS, is silently unprotected. An attacker can upload an SVG file containing arbitrary JavaScript; if the application serves that SVG inline from its own origin, the script executes in the victim's browser, resulting in stored XSS. This issue has been fixed in versions 2.2.7 and 3.1.3.