CVE-2026-34715
ewe Has Improper Neutralization of CRLF Sequences in HTTP Headers (HTTP Request/Response Splitting)
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
- vshakitskiy · ewe
- CVSS v3.1 NVD
- 5.3 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N - EPSS
- 0.41% chance of exploitation in the next 30 days, 34th percentile
- Published
- 2026-04-02
- Updated
- 2026-04-03
Proof-of-concept exploits (1)
Security advisories
- vshakitskiy/ewe/security/advisories/GHSA-x2w3-23jr-hrpf
- vshakitskiy/ewe/commit/ce4ff214d32626a10fda9398dc94a2d720e17446