{"id":"CVE-2026-32881","aliases":["GHSA-9w88-79f8-m3vp"],"url":"https://o3.security/vulnerability/CVE-2026-32881","summary":"ewe has an Overly Permissive List of Allowed Inputs","details":"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.","published":"2026-03-20T01:18:55.382Z","modified":"2026-07-15T01:48:52.294359664Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Hex","name":"ewe","fixedVersion":"3.0.5"}],"fix":{"url":"https://github.com/vshakitskiy/ewe/commit/07dcfd2135fc95f38c17a9d030de3d7efee1ee39","label":"vshakitskiy/ewe@07dcfd2"},"references":[{"type":"WEB","url":"https://github.com/vshakitskiy/ewe/releases/tag/v3.0.5"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32881.json"},{"type":"ADVISORY","url":"https://github.com/vshakitskiy/ewe/security/advisories/GHSA-9w88-79f8-m3vp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32881"},{"type":"FIX","url":"https://github.com/vshakitskiy/ewe/commit/07dcfd2135fc95f38c17a9d030de3d7efee1ee39"},{"type":"FIX","url":"https://github.com/vshakitskiy/ewe/commit/94ab6e7bf7293e987ae98b4daa51ea131c2671ba"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:48:52.294359664Z"}}