Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Sendfile#map_accel_path interpolates the value of the X-Accel-Mapping request header directly into a regular expression when rewriting file paths for X-Accel-Redirect. Because the header value is not escaped, an attacker who can supply X-Accel-Mapping to the backend can inject regex metacharacters and control the generated X-Accel-Redirect response header. In deployments using Rack::Sendfile with x-accel-redirect, this can allow an attacker to cause nginx to serve unintended files from configured internal locations. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | Upgrade ruby-rack | Aug 2, 2026 | Aug 2, 2026 |
| Redhat_linux | — | No solution exists | Jul 17, 2026 | Apr 2, 2026 |
| Ubuntu | — | Upgrade ruby-rack (Ubuntu Pro)Upgrade librack-ruby1.8 (Ubuntu Pro)Upgrade librack-ruby (Ubuntu Pro)Upgrade librack-ruby1.9.1 (Ubuntu Pro)Upgrade ruby-rack | Apr 20, 2026 | Apr 17, 2026 |
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