Description
An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3. 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 query string after a ? character) followed by an HTTP header or a Redis command. This is fixed in: v2.7.17, v2.7.17rc1, v2.7.18, v2.7.18rc1; v3.5.10, v3.5.10rc1, v3.5.8, v3.5.8rc1, v3.5.8rc2, v3.5.9; v3.6.10, v3.6.10rc1, v3.6.11, v3.6.11rc1, v3.6.12, v3.6.9, v3.6.9rc1; v3.7.4, v3.7.4rc1, v3.7.4rc2, v3.7.5, v3.7.5rc1, v3.7.6, v3.7.6rc1, v3.7.7, v3.7.7rc1, v3.7.8, v3.7.8rc1, v3.7.9.
Published: 2019-03-13
Score: 6.1 Medium
EPSS: 5.4% Low
KEV: No
AI Analysis

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Remediation

No solution or workaround provided in the CVE record.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-1834-1 python2.7 security update
Debian DLA Debian DLA DLA-1835-1 python3.4 security update
Debian DLA Debian DLA DLA-1835-2 python3.4 regression update
Debian DLA Debian DLA DLA-2280-1 python3.5 security update
Debian DLA Debian DLA DLA-2337-1 python2.7 security update
Debian DLA Debian DLA DLA-3610-1 python-urllib3 security update
EUVD EUVD EUVD-2019-19103 An issue was discovered in urllib2 in Python 2.x through 2.7.16 and urllib in Python 3.x through 3.7.3. 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 query string after a ? character) followed by an HTTP header or a Redis command. This is fixed in: v2.7.17, v2.7.17rc1, v2.7.18, v2.7.18rc1; v3.5.10, v3.5.10rc1, v3.5.8, v3.5.8rc1, v3.5.8rc2, v3.5.9; v3.6.10, v3.6.10rc1, v3.6.11, v3.6.11rc1, v3.6.12, v3.6.9, v3.6.9rc1; v3.7.4, v3.7.4rc1, v3.7.4rc2, v3.7.5, v3.7.5rc1, v3.7.6, v3.7.6rc1, v3.7.7, v3.7.7rc1, v3.7.8, v3.7.8rc1, v3.7.9.
Ubuntu USN Ubuntu USN USN-4127-1 Python vulnerabilities
Ubuntu USN Ubuntu USN USN-4127-2 Python vulnerabilities
Ubuntu USN Ubuntu USN USN-6891-1 Python vulnerabilities
References
Link Providers
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00039.html cve-icon cve-icon
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00041.html cve-icon cve-icon
http://packetstormsecurity.com/files/154927/Slackware-Security-Advisory-python-Updates.html cve-icon cve-icon
http://www.openwall.com/lists/oss-security/2021/02/04/2 cve-icon cve-icon
http://www.securityfocus.com/bid/107466 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2019:1260 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2019:2030 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2019:3335 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2019:3520 cve-icon cve-icon
https://access.redhat.com/errata/RHSA-2019:3725 cve-icon cve-icon
https://bugs.python.org/issue36276 cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2019/06/msg00022.html cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2019/06/msg00023.html cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2019/06/msg00026.html cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2020/08/msg00034.html cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ORNTF62QPLMJXIQ7KTZQ2776LMIXEKL/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/44TS66GJMO5H3RLMVZEBGEFTB6O2LJJU/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X3HW5JRZ7GCPSR7UHJOLD7AWLTQCDVR/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JCPGLTTOBB3QEARDX4JOYURP6ELNNA2V/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JMWSKTNOHSUOT3L25QFJAVCFYZX46FYK/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JXASHCDD4PQFKTMKQN4YOP5ZH366ABN4/ cve-icon cve-icon
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M34WOYCDKTDE5KLUACE2YIEH7D37KHRX/ cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2019-9740 cve-icon
https://seclists.org/bugtraq/2019/Oct/29 cve-icon cve-icon
https://security.gentoo.org/glsa/202003-26 cve-icon cve-icon
https://security.netapp.com/advisory/ntap-20190619-0005/ cve-icon cve-icon
https://usn.ubuntu.com/4127-1/ cve-icon cve-icon
https://usn.ubuntu.com/4127-2/ cve-icon cve-icon
https://www.cve.org/CVERecord?id=CVE-2019-9740 cve-icon
https://www.oracle.com/security-alerts/cpujul2022.html cve-icon cve-icon
History

Wed, 07 Oct 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 6.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N'}

 ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'}

Sat, 12 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.08532}

 epss

{'score': 0.08653}

Subscriptions

Python Python
Redhat Ansible Tower Enterprise Linux Rhel Aus Rhel E4s Rhel Eus Rhel Software Collections Rhel Tus
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-10-07T18:22:51.355Z

Reserved: 2019-03-12T00:00:00.000Z

Link: CVE-2019-9740

cve-icon Vulnrichment

Updated: 2024-08-04T22:01:54.079Z

cve-icon NVD

Status : Modified

Published: 2019-03-13T03:29:00.193

Modified: 2026-10-07T19:17:15.167

Link: CVE-2019-9740

cve-icon Redhat

Severity : Moderate

Publid Date: 2019-03-13T00:00:00Z

Links: CVE-2019-9740 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses
  • CWE-113

    Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')

  • CWE-93

    Improper Neutralization of CRLF Sequences ('CRLF Injection')