CVE-2026-34230
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Summary
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.select_best_encoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard (*) entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted Accept-Encoding header and cause disproportionate CPU consumption on the compression middleware path. This results in a denial of service condition for applications using Rack::Deflater. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
Affected Software
| Vendor | Product | Version Range | Status |
|---|---|---|---|
| rack | rack | < 2.2.23 | affected |
| rack | rack | >= 3.0.0.beta1, < 3.1.21 | affected |
| rack | rack | >= 3.2.0, < 3.2.6 | affected |
Weaknesses
- CWE-400: CWE-400: Uncontrolled Resource Consumption
- CWE-407: CWE-407: Inefficient Algorithmic Complexity
ADP Enrichment
CISA ADP Vulnrichment
- SSVC:
- Exploitation: none
- Automatable: yes
- Technical Impact: partial
References
Feedback
Was this page helpful?
Glad to hear it! Please tell us how we can improve.
Sorry to hear that. Please tell us how we can improve.