Disclosure summary
http.client in Python 3.x before 3.5.10, 3.6.x before 3.6.12, 3.7.x before 3.7.9, and 3.8.x before 3.8.5 allows CRLF injection if the attacker controls the HTTP request method, as demonstrated by inserting CR and LF control characters in the first argument of HTTPConnection.request.
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-2020-26116
Open original source · Updated Oct 08, 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":"3.8.5"} |
| fedoraproject | fedora | 31 |
| fedoraproject | fedora | 32 |
| fedoraproject | fedora | 33 |
| canonical | ubuntu_linux | 12.04 |
| canonical | ubuntu_linux | 14.04 |
| canonical | ubuntu_linux | 16.04 |
| canonical | ubuntu_linux | 18.04 |
| netapp | solidfire | - |
| netapp | hci_storage_node | - |
| debian | debian_linux | 9.0 |
| oracle | zfs_storage_appliance_kit | 8.8 |
| opensuse | leap | 15.1 |
Original records & references
- NIST NVD record
- CVE Program record
- bugs.python.org — Exploit, Issue Tracking, Patch, Vendor Advisory
- lists.debian.org — Mailing List, Third Party Advisory
- lists.debian.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- python-security.readthedocs.io — Patch, Third Party Advisory
- security.gentoo.org — Third Party Advisory
- security.netapp.com — Third Party Advisory
- usn.ubuntu.com — Third Party Advisory
- www.oracle.com — Patch, Third Party Advisory
- bugs.python.org — Exploit, Issue Tracking, Patch, Vendor Advisory
- lists.debian.org — Mailing List, Third Party Advisory
- lists.debian.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- lists.fedoraproject.org
- python-security.readthedocs.io — Patch, Third Party Advisory
- security.gentoo.org — Third Party Advisory
- security.netapp.com — Third Party Advisory
- usn.ubuntu.com — Third Party Advisory
- www.oracle.com — Patch, Third Party Advisory
PUBLISHED 2020-09-27T00:15:11-04:00
MODIFIED 2026-10-08T17:17:26-04:00
INGESTED 2026-10-10T20:50:19-04:00