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CVE-2008-3656

HIGH severity · CVSS 7.8 · CWE-399
7.8CVSS HIGH

Summary

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.

Impact & exploitability

Attack vectorNetwork
Attack complexityLow
Privileges required
User interaction
Confidentiality impactNone
Integrity impactNone
Availability impact
Exploit probability (EPSS)79%

AV:N/AC:L/Au:N/C:N/I:N/A:C

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Last checked: Wed, 10 Jun 2026 22:18:30 UTC