CVE-2026-34715
ewe Has Improper Neutralization of CRLF Sequences in HTTP Headers (HTTP Request/Response Splitting)
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| erlang | ewe | < 3.0.6 | 3.0.6 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Vshakitskiy | Ewe | before 3.0.6 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-x2w3-23jr-hrpf
- https://github.com/vshakitskiy/ewe/security/advisories/GHSA-x2w3-23jr-hrpf
- https://nvd.nist.gov/vuln/detail/CVE-2026-34715
- https://github.com/vshakitskiy/ewe/commit/ce4ff214d32626a10fda9398dc94a2d720e17446
- https://github.com/vshakitskiy/ewe/releases/tag/v3.0.6