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Rack::Request accepts invalid Host characters, enabling host allowlist bypass

Rack::Request accepts invalid Host characters, enabling host allowlist bypass

CVE-2026-34835Published 5 months agoUpdated 5 days agoSource: OSV

Affected packages

  • rack3.0.0.beta1 → 3.1.21

Exploit signal

Known exploited (CISA KEV)
No
EPSS score
EPSS percentile

EPSS is the probability a CVE is exploited in the wild; percentile is its rank among all CVEs.

Rack::Request accepts invalid Host characters, enabling host allowlist bypass | HackTribune