VulnerabilityModified

CVE-2026-34785

As a result, files under the static root whose names merely share the configured prefix may be served unintentionally, leading to information disclosure.

HIGH 7.5EPSS 0.39%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.39%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Static determines whether a request should be served as a static file using a simple string prefix check. When configured with URL prefixes such as "/css", it matches any request path that begins with that string, including unrelated paths such as "/css-config.env" or "/css-backup.sql". As a result, files under the static root whose names merely share the configured prefix may be served unintentionally, leading to information disclosure. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

CVSS 3.1: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS: 0.39% probability · 32th percentile
CISA KEV: Not listed
Weakness: CWE-187, CWE-200, CWE-552
Affected: rack/rack
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.