Rack is a modular Ruby web server interface. Prior to version 2.2.18, Rack::QueryParser enforces its params_limit only for parameters separated by &, while still splitting on both & and ;. As a result, attackers could use ; separators to bypass the parameter count limit and submit more parameters than intended. Applications or middleware that directly invoke Rack::QueryParser with its default configuration (no explicit delimiter) could be exposed to increased CPU and memory consumption. This can be abused as a limited denial-of-service vector. This issue has been patched in version 2.2.18.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade pcsUpgrade pcs-snmp | Nov 21, 2025 | Nov 4, 2025 |
| Debian | — | Upgrade ruby-rack | Nov 4, 2025 | Nov 4, 2025 |
| Oracle_linux | — | Upgrade pcsUpgrade pcs-snmpUpgrade cockpit-ha-cluster | Nov 5, 2025 | Sep 25, 2025 |
| Redhat_linux | — | Upgrade pcsUpgrade pcs-snmpUpgrade cockpit-ha-cluster | Nov 5, 2025 | Sep 25, 2025 |
| Rocky_linux | — | Upgrade pcs-snmpUpgrade pcs | Feb 5, 2026 | Nov 21, 2025 |
| Ubuntu | — | Upgrade ruby-rackUpgrade ruby-rack (Ubuntu Pro) | Sep 30, 2025 | Sep 26, 2025 |
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