Skip to content
OpenAdvisories
Medium · 5.3 CVE-2026-32881 EUVD-2026-13431GHSA-9w88-79f8-m3vp

ewe has an Overly Permissive List of Allowed Inputs

Published Mar 20, 2026 · Updated Mar 20, 2026 · Assigned by GitHub_M

Description

ewe is a Gleam web server. ewe is a Gleam web server. Versions 0.6.0 through 3.0.4 are vulnerable to authentication bypass or spoofed proxy-trust headers. Chunked transfer encoding trailer handling merges declared trailer fields into req.headers after body parsing, but the denylist only blocks 9 header names. A malicious client can exploit this by declaring these headers in the Trailer field and appending them after the final chunk, causing request.set_header to overwrite legitimate values (e.g., those set by a reverse proxy). This enables attackers to forge authentication credentials, hijack sessions, bypass IP-based rate limiting, or spoof proxy-trust headers in any downstream middleware that reads headers after ewe.read_body is called. This issue has been fixed in version 3.0.5.

Affected products

VendorProductAffectedFixed
vshakitskiy ewe >= 0.6.0, < 3.0.5 —

Affected packages

EcosystemPackageAffectedFixedRecord
Hex ewe >= 0.6.0, < 3.0.5 3.0.5 GHSA-9w88-79f8-m3vp

References