CVE-2026-44587 is a medium-severity security vulnerability in carrierwave (rubygems), affecting versions >= 3.0.0.beta, < 3.1.3. It is fixed in 3.1.3, 2.2.7.
Summary CarrierWave's contenttypedenylist check fails to escape regex metacharacters in string entries, causing the denylist to silently not match the content types it is intended to block. Note: CarrierWave is aware #contenttypedenylist is deprecated for the security reason, but it still used by developers, and the problem here isn't denylist allows any filetype, and thats not a vulnerability in carrierwave, its an implementation problem in developers using CarrierWave, the problem is its denylist entries are interpolated directly into a regex without Regexp.quote or anchoring. The denylist is still useful when developers want to ban specific content types but allow everything else. Details In lib/carrierwave/uploader/contenttypedenylist.rb:57, string denylist entries are interpolated directly into a regex without Regexp.quote or anchoring: Other affected MIME types include application/xhtml+xml and any type containing regex metacharacters. Fix: Apply Regexp.quote for string entries and anchor with \A, matching the existing allowlist implementation: PoC Expected response (denylist working): Actual response: Impact Any application that uses contenttypedenylist to block image/svg+xml, the most common use case, specifically to prevent stored XSS, is silently unprotected. An attacker can upload an SVG file containing arbitrary
CVE-2026-44587 has a CVSS score of 4.7 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (3.1.3, 2.2.7). Upgrading removes the vulnerable code path.
rubygems
carrierwave (>= 3.0.0.beta, < 3.1.3)carrierwave (< 2.2.7)carrierwave → 3.1.3 (rubygems)carrierwave → 2.2.7 (rubygems)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.
Kodem's runtime-powered SCA identifies whether CVE-2026-44587 is reachable in your applications. Explore open-source security for your team.
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Upgrade the following packages to resolve this vulnerability:
carrierwave to 3.1.3 or latercarrierwave to 2.2.7 or laterKodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-44587 is a medium-severity security vulnerability in carrierwave (rubygems), affecting versions >= 3.0.0.beta, < 3.1.3. It is fixed in 3.1.3, 2.2.7.
CVE-2026-44587 has a CVSS score of 4.7 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
carrierwave (rubygems) versions >= 3.0.0.beta, < 3.1.3 is affected.
Yes. CVE-2026-44587 is fixed in 3.1.3, 2.2.7. Upgrade to this version or later.
Whether CVE-2026-44587 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
carrierwave to 3.1.3 or latercarrierwave to 2.2.7 or later