{"cve":"CVE-2018-1000164","nvd":{"published":"2018-04-18T19:29:00.707","modified":"2026-06-17T01:32:34.163","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","score":7.5},"cwes":["CWE-93"],"references":["https://epadillas.github.io/2018/04/02/http-header-splitting-in-gunicorn-19.4.5","https://github.com/benoitc/gunicorn/issues/1227","https://lists.debian.org/debian-lts-announce/2018/04/msg00022.html","https://usn.ubuntu.com/4022-1/","https://www.debian.org/security/2018/dsa-4186"],"products":["debian:debian_linux","gunicorn:gunicorn"],"source":"nvd","synced_at":"2026-10-19T20:49:59.483420567+00:00"},"epss":{"cve":"CVE-2018-1000164","score":0.02369,"percentile":0.83825,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-32pc-xphx-q4f6","url":"https://osv.dev/vulnerability/GHSA-32pc-xphx-q4f6","summary":"Gunicorn contains Improper Neutralization of CRLF sequences in HTTP headers","modified":"2026-09-08T15:46:56.599254Z","packages":[{"ecosystem":"PyPI","name":"gunicorn","purl":"pkg:pypi/gunicorn","ranges":["<19.5.0"],"fixed":["19.5.0"]}]},{"id":"PYSEC-2018-55","url":"https://osv.dev/vulnerability/PYSEC-2018-55","summary":"","modified":"2023-11-08T03:59:36.379813Z","packages":[{"ecosystem":"PyPI","name":"gunicorn","purl":"pkg:pypi/gunicorn","ranges":["<19.5.0"],"fixed":["19.5.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}