Disclosure summary
An issue was discovered in urllib2 in Python 2.x through 2.7.17 and urllib in Python 3.x through 3.8.0. CRLF injection is possible if the attacker controls a url parameter, as demonstrated by the first argument to urllib.request.urlopen with \r\n (specifically in the host component of a URL) followed by an HTTP header. This is similar to the CVE-2019-9740 query string issue and the CVE-2019-9947 path string issue. (This is not exploitable when glibc has CVE-2016-10739 fixed.). This is fixed in: v2.7.18, v2.7.18rc1; v3.5.10, v3.5.10rc1; v3.6.11, v3.6.11rc1, v3.6.12; v3.7.8, v3.7.8rc1, v3.7.9; v3.8.3, v3.8.3rc1, v3.8.4, v3.8.4rc1, v3.8.5, v3.8.6, v3.8.6rc1.
Source-reported weakness categories
CWE-74
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2019-18348
Open original source · Updated Oct 07, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| python | python | * {"versionStartIncluding":"3.8.0","versionEndExcluding":"3.8.3"} |
Original records & references
- NIST NVD record
- CVE Program record
- bugs.python.org — Issue Tracking, Vendor Advisory
- bugzilla.redhat.com — Issue Tracking, Third Party Advisory
- lists.debian.org — Mailing List, Technical Description
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- security.netapp.com — Technical Description
- usn.ubuntu.com — Technical Description
- usn.ubuntu.com — Technical Description
- www.oracle.com — Technical Description
- bugs.python.org — Issue Tracking, Vendor Advisory
- bugzilla.redhat.com — Issue Tracking, Third Party Advisory
- lists.debian.org — Mailing List, Technical Description
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- security.netapp.com — Technical Description
- usn.ubuntu.com — Technical Description
- usn.ubuntu.com — Technical Description
- www.oracle.com — Technical Description
PUBLISHED 2019-10-23T13:15:12-04:00
MODIFIED 2026-10-07T15:17:13-04:00
INGESTED 2026-10-08T12:30:34-04:00