medium6.3
CVE-2026-61846
Crass: Deeply nested CSS blocks and functions can trigger a SystemStackError or excessive memory usage
Impact
Crass is a Ruby CSS parser that's fully compliant with the CSS Syntax Level 3 specification. Prior to 1.0.7, Crass recursively parses `CSS simple blocks and functions` without a depth guard. An attacker-controlled CSS value containing deeply nested blocks or functions can recurse until Ruby raises `SystemStackError`: stack level too deep, or cause excessive memory usage. Version 1.0.7 adds a configurable depth limit with a conservative default. This issue is fixed in version 1.0.7.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| rubygems | crass | < 1.0.7 | 1.0.7 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Rgrove | Crass | before 1.0.7 |