carrierwaveuploader carrierwave up to 2.2.6/3.1.2 SVG File content_type_denylist.rb permissive regular expression

Summaryinfo

A vulnerability marked as critical has been reported in carrierwaveuploader carrierwave up to 2.2.6/3.1.2. The affected element is an unknown function in the library lib/carrierwave/uploader/content_type_denylist.rb of the component SVG File Handler. Performing a manipulation results in permissive regular expression. This vulnerability is reported as CVE-2026-44587. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in carrierwaveuploader carrierwave up to 2.2.6/3.1.2. This affects an unknown code in the library lib/carrierwave/uploader/content_type_denylist.rb of the component SVG File Handler. The manipulation with an unknown input leads to a permissive regular expression vulnerability. CWE is classifying the issue as CWE-625. The product uses a regular expression that does not sufficiently restrict the set of allowed values. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-44587 since 05/06/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 321723 (Linux Distros Unpatched Vulnerability : CVE-2026-44587), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 2.2.7 or 3.1.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (321723). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Vendor

• carrierwaveuploader

Name

• carrierwave

Version

• 2.2.0
• 2.2.1
• 2.2.2
• 2.2.3
• 2.2.4
• 2.2.5
• 2.2.6
• 3.1.0
• 3.1.1
• 3.1.2

Website

• Product: https://github.com/carrierwaveuploader/carrierwave/

CPE 2.3info

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CPE 2.2info

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Be aware that VulDB is the high quality source for vulnerability data.

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