Medium
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2019-18348
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 08:04 UTC · Revision 1
Source evidence
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.
osv:CVE-2019-18348
Complete source record
{
"id": "25c3fad61e3d7c21c01cee3c4ba6bc38291280ee10bb3197efafe6782e92d932",
"url": "https://osv.dev/vulnerability/CVE-2019-18348",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2019-18348",
"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.",
"evidence": "osv:CVE-2019-18348",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2019-18348",
"aliases": [
"CVE-2019-18348",
"PSF-2019-7"
],
"metrics": [
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"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
}
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"affected": [
{
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"range": [
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{
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"versions": [
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"v3.8.3rc1",
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"v3.5.0rc2",
"v3.5.0rc1",
"v3.5.0b4",
"v3.5.0b3",
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"v2.7.10rc1",
"v3.5.0a4",
"v3.5.0a3",
"v3.5.0a2",
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"v2.7.9rc1",
"v2.7.8",
"v3.4.0b3",
"v3.4.0b2",
"v3.4.0b1",
"v2.7.6rc1",
"v3.4.0a4",
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],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2019-18348.json"
}
}
],
"modified": "2026-10-24T10:31:02.541330003Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X3HW5JRZ7GCPSR7UHJOLD7AWLTQCDVR/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A5NSAX4SC3V64PGZUPH7PRDLSON34Q5A/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JCPGLTTOBB3QEARDX4JOYURP6ELNNA2V/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M34WOYCDKTDE5KLUACE2YIEH7D37KHRX/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UESGYI5XDAHJBATEZN3MHNDUBDH47AS6/",
"https://bugs.python.org/issue30458#msg347282",
"https://bugzilla.redhat.com/show_bug.cgi?id=1727276",
"https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html",
"https://security.netapp.com/advisory/ntap-20191107-0004/",
"https://usn.ubuntu.com/4333-1/",
"https://usn.ubuntu.com/4333-2/",
"https://www.oracle.com/security-alerts/cpuoct2020.html"
],
"provider_metadata": {}
},
"related_cves": [
{
"value": "CVE-2019-18348",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 440040,
"published_at": "2019-10-23T17:15:12.973+00:00"
}