Vulnerability in Rack Web Server Interface Affects File Path Security
CVE-2026-34830

5.9MEDIUM

Key Information:

Vendor

Rack

Status
Rack
Vendor
CVE Published:
2 April 2026

What is CVE-2026-34830?

The Rack web server interface prior to versions 2.2.23, 3.1.21, and 3.2.6 is vulnerable to regex injection due to improper handling of the X-Accel-Mapping request header in Rack::Sendfile#map_accel_path. An attacker can exploit this vulnerability to manipulate regex metacharacters, potentially allowing unauthorized access to sensitive files served by nginx in a misconfigured deployment. This security flaw emphasizes the importance of proper input sanitation to prevent exploitation and safeguard file path integrity.

Affected Version(s)

rack < 2.2.23 < 2.2.23

rack >= 3.0.0.beta1, < 3.1.21 < 3.0.0.beta1, 3.1.21

rack >= 3.2.0, < 3.2.6 < 3.2.0, 3.2.6

References

https://github.com/rack/rack/security/advisories/GHSA-qv7...
x_refsource_CONFIRM

CVSS V3.1

Score:
5.9
Severity:
MEDIUM
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.