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Medium severity5.9NVD Advisory· Published Apr 2, 2026· Updated Apr 16, 2026

CVE-2026-34830

CVE-2026-34830

Description

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.

AI Insight

LLM-synthesized narrative grounded in this CVE's description and references.

Affected packages

Versions sourced from the GitHub Security Advisory.

PackageAffected versionsPatched versions
rackRubyGems
< 2.2.232.2.23
rackRubyGems
>= 3.0.0.beta1, < 3.1.213.1.21
rackRubyGems
>= 3.2.0, < 3.2.63.2.6

Affected products

65

Patches

Vulnerability mechanics

References

4

News mentions

0

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