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TI-2026-27029 Aliases CVE-2026-34785GHSA-h2jq-g4cq-5ppq

Rack: Local file inclusion in `Rack::Static` via URL Prefix Matching

Priority LOW 39CWE-187Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-200.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00394 33rd percentileScored 2026-11-07
Fix Fixed rack (rack): 2.2.23, 3.1.21, 3.2.6rack (RubyGems): 2.2.23, 3.1.21, 3.2.6

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
rackrackbefore 2.2.23; 3.0.0.beta1 to before 3.1.21; 3.2.0 to before 3.2.62.2.23, 3.1.21, 3.2.6Patch availableCNA
—rack (RubyGems)before 2.2.232.2.23Patch availableGHSA-h2jq-g4cq-5ppq
—rack (RubyGems)3.0.0.beta1 to before 3.1.213.1.21Patch availableGHSA-h2jq-g4cq-5ppq
—rack (RubyGems)3.2.0 to before 3.2.63.2.6Patch availableGHSA-h2jq-g4cq-5ppq
  • rack Vendorrack Affected before 2.2.23; 3.0.0.beta1 to before 3.1.21; 3.2.0 to before 3.2.6 Fixed in 2.2.23, 3.1.21, 3.2.6 Patch available CNA
  • rack (RubyGems) Vendor— Affected before 2.2.23 Fixed in 2.2.23 Patch available GHSA-h2jq-g4cq-5ppq
  • rack (RubyGems) Vendor— Affected 3.0.0.beta1 to before 3.1.21 Fixed in 3.1.21 Patch available GHSA-h2jq-g4cq-5ppq
  • rack (RubyGems) Vendor— Affected 3.2.0 to before 3.2.6 Fixed in 3.2.6 Patch available GHSA-h2jq-g4cq-5ppq

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*before 2.2.23; 3.0.0 to before 3.1.21; 3.2.0 to before 3.2.6Vulnerablerack
  • cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:* Versions before 2.2.23; 3.0.0 to before 3.1.21; 3.2.0 to before 3.2.6 Vulnerable ·rack

Remediation

  • Fix · CNA rack (rack) Fixed in 2.2.23, 3.1.21, 3.2.6
  • Fix · GHSA-h2jq-g4cq-5ppq rack (RubyGems) Fixed in 2.2.23 Advisory →
  • Fix · GHSA-h2jq-g4cq-5ppq rack (RubyGems) Fixed in 3.1.21 Advisory →
  • Fix · GHSA-h2jq-g4cq-5ppq rack (RubyGems) Fixed in 3.2.6 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat Satellite 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-34785
  2. 2026-10-03 Alias added: GHSA-h2jq-g4cq-5ppq

References

Advisory 2

Other 2

  • TI-2024-16580 Rack ReDos in content type parsing (2nd degree polynomial) CVSS 3.1HIGH 7.5
  • TI-2024-17236 Possible Denial of Service Vulnerability in Rack Header Parsing CVSS 3.1HIGH 7.5
  • TI-2024-17231 Possible DoS Vulnerability with Range Header in Rack CVSS 3.1HIGH 7.5
  • TI-2023-12254 Uncontrolled resource consumption in https://github.com/rack/rack CVSS 3.1HIGH 7.5
  • TI-2025-38165 Rack's multipart parser buffers unbounded per-part headers, enabling DoS (memory exhaustion) CVSS 3.1HIGH 7.5
  • TI-2025-38163 Rack's unbounded multipart preamble buffering enables DoS (memory exhaustion) CVSS 3.1HIGH 7.5
See all 36 →

Sources

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