Vulnerability in Vshakitskiy Ewe
CVE-2026-32881
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 · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.005 (40.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001
Affected products
- Vshakitskiy Ewe — versions >= 0.6.0, < 3.0.5
Weakness classification (CWE)
References
- github.com/vshakitskiy/ewe/security/advisories/GHSA-9w88-79f8-m3vp (Exploit, Mitigation, Vendor Advisory)
- github.com/vshakitskiy/ewe/commit/07dcfd2135fc95f38c17a9d030de3d7efee1ee39 (Patch)
- github.com/vshakitskiy/ewe/commit/94ab6e7bf7293e987ae98b4daa51ea131c2671ba (Patch)
- github.com/vshakitskiy/ewe/releases/tag/v3.0.5 (Product, Patch)
Frequently asked questions
- What is CVE-2026-32881?
- CVE-2026-32881 is a medium-severity vulnerability in Vshakitskiy Ewe, classified under CWE-183. CVSS score: 5.3/10. Published 2026-03-20.
- How severe is CVE-2026-32881?
- Medium severity. CVSS v3 base score is 5.3 out of 10.