CVE-2008-3656: Ruby-Lang Ruby

High severity, CVSS 7.8. EPSS: 70.2% chance of exploitation in the next 30 days.

Algorithmic complexity vulnerability in the WEBrick::HTTPUtils.split_header_value function in WEBrick::HTTP::DefaultFileHandler in WEBrick in Ruby 1.8.5 and earlier, 1.8.6 through 1.8.6-p286, 1.8.7 through 1.8.7-p71, and 1.9 through r18423 allows context-dependent attackers to cause a denial of service (CPU consumption) via a crafted HTTP request that is processed by a backtracking regular expression.

Affected products

• Ruby-Lang Ruby: up to and including 1.8.5; version 1.6.8 only; version 1.8.0 only; version 1.8.1 only; version 1.8.2 only; version 1.8.3 only; …

Published 2008-08-13. Last modified 2026-06-16.