Gunicorn contains Improper Neutralization of CRLF sequences in HTTP headers
gunicorn version 19.4.5 contains a CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers vulnerability in "process_headers" function in "gunicorn/http/wsgi.py" that can result in an attacker causing the server to return arbitrary HTTP headers. This vulnerability appears to have been fixed in 19.5.0.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | gunicorn | < 19.5.0 | 19.5.0 |
References
- https://github.com/benoitc/gunicorn/issues/1227
- https://epadillas.github.io/2018/04/02/http-header-splitting-in-gunicorn-19.4.5
- https://lists.debian.org/debian-lts-announce/2018/04/msg00022.html
- https://www.debian.org/security/2018/dsa-4186
- https://usn.ubuntu.com/4022-1/
- https://github.com/advisories/GHSA-32pc-xphx-q4f6
- https://nvd.nist.gov/vuln/detail/CVE-2018-1000164
- https://github.com/benoitc/gunicorn/commit/1e10a02e73c87dfadc394b361af33864d0e59e24
- https://github.com/benoitc/gunicorn
- https://github.com/pypa/advisory-database/tree/main/vulns/gunicorn/PYSEC-2018-55.yaml
- https://usn.ubuntu.com/4022-1
- CVSS vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N- Weakness (CWE)
CWE-93- Platform
- Python (PyPI)
- Package
gunicorn- Disclosed
- 18.04.2018
- Updated
- 11.10.2026 15:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2018-55 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-32pc-xphx-q4f6 - CC BY 4.0
Vulnerability history: gunicorn
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 3
- First → latest
- 04.2018 03.2025
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 3
Disclosures per year
- 2018: 1
- 2019: 0
- 2020: 0
- 2021: 0
- 2022: 0
- 2023: 0
- 2024: 1
- 2025: 1
- 2026: 0
-
Gunicorn contains Improper Neutralization of CRLF sequences in HTTP headers this entry
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