CVE-2026-34715: Vshakitskiy Ewe

Medium severity, CVSS 5.3. EPSS: 0.4% chance of exploitation in the next 30 days.

ewe is a Gleam web server. Prior to version 3.0.6, the encode_headers function in src/ewe/internal/encoder.gleam directly interpolates response header keys and values into raw HTTP bytes without validating or stripping CRLF (\r\n) sequences. An application that passes user-controlled data into response headers (e.g., setting a Location redirect header from a request parameter) allows an attacker to inject arbitrary HTTP response content, leading to response splitting, cache poisoning, and possible cross-site scripting. Notably, ewe does validate CRLF in incoming request headers via validate_field_value() in the HTTP/1.1 parser — but provides no equivalent protection for outgoing response headers in the encoder. This issue has been patched in version 3.0.6.

Affected products

• Vshakitskiy Ewe: before 3.0.6 (fixed in 3.0.6)

Published 2026-04-02. Last modified 2026-07-24.