High
Security advisory
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2020-26116
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 08:03 UTC · Revision 1
Source evidence
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.
osv:CVE-2020-26116
Complete source record
{
"id": "45497ef0dccc2e538537383d699db3cd227ed6f3d3790d01f5d32b4eed256e57",
"url": "https://osv.dev/vulnerability/CVE-2020-26116",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2020-26116",
"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.",
"evidence": "osv:CVE-2020-26116",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2020-26116",
"aliases": [
"BIT-libpython-2020-26116",
"BIT-python-2020-26116",
"BIT-python-min-2020-26116",
"CVE-2020-26116",
"PSF-2020-5"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/python/cpython",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "426b022776672fdf3d71ddd98d89af341c88080f"
},
{
"introduced": "5c4568a05a0a62b5947c55f68f9f2ecfb90a4f12"
},
{
"fixed": "c0a9afe2ac1820409e6173bd1893ebee2cf50270"
},
{
"introduced": "1bf9cc509326bc42cd8cb1650eb9bf64550d817e"
},
{
"fixed": "13c94747c74437e594b7fc242ff7da668e81887c"
},
{
"introduced": "fa919fdf2583bdfead1df00e842f24f30b2a34bf"
},
{
"fixed": "580fbb018fd0844806119614d752b41fc69660f9"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.0.0"
},
{
"fixed": "3.5.10"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.6.0"
},
{
"fixed": "3.6.12"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.7.0"
},
{
"fixed": "3.7.9"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:python:python:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "3.8.0"
},
{
"fixed": "3.8.5"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
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"v3.7.8",
"v3.6.11",
"v3.6.11rc1",
"v3.7.8rc1",
"v3.8.3",
"v3.8.3rc1",
"v3.7.7rc1",
"v3.6.10",
"v3.6.10rc1",
"v3.7.6rc1",
"v3.5.9",
"v3.5.8",
"v3.5.8rc2",
"v3.5.8rc1",
"v3.8.0rc1",
"v3.6.9",
"v3.6.9rc1",
"v3.7.3rc1",
"v3.5.7",
"v3.5.7rc1",
"v3.6.8",
"v3.7.2rc1",
"v3.6.8rc1",
"v3.5.6",
"v3.5.6rc1",
"v3.7.0rc1",
"v3.6.6rc1",
"v3.7.0b5",
"v3.7.0b4",
"v3.7.0b3",
"v3.7.0b2",
"v3.5.5",
"v3.5.5rc1",
"v3.7.0b1",
"v3.7.0a2",
"v3.5.4",
"v3.5.4rc1",
"v3.6.2rc1",
"v3.5.3",
"v3.5.3rc1",
"v3.6.0rc1",
"v3.6.0b4",
"v3.6.0b3",
"v3.6.0b1",
"v3.6.0a3",
"v3.5.2",
"v3.5.2rc1",
"v3.5.1rc1",
"v3.5.0rc3",
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"v3.5.0rc1",
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"v3.5.0b1",
"v3.5.0a4",
"v3.5.0a3",
"v3.5.0a2",
"v3.5.0a1",
"v3.4.0b3",
"v3.4.0b2",
"v3.4.0b1",
"v3.4.0a4",
"v3.4.0a3",
"v3.4.0a2",
"v3.4.0a1",
"v3.3.0rc3",
"v3.3.0rc2",
"v3.3.0rc1",
"v3.3.0b2",
"v3.3.0b1",
"v3.3.0a4",
"v3.3.0a3",
"v3.3.0a2",
"v3.2rc3",
"v3.2rc2",
"v3.2rc1",
"v3.2b2",
"v3.2b1",
"v3.2a4",
"v3.2a3",
"v3.2a2",
"v3.2a1",
"v3.1",
"v3.1rc2",
"v3.1rc1",
"v3.1b1",
"v3.1a2",
"v3.1a1",
"v3.0rc3",
"v3.0rc2",
"v3.0rc1",
"v3.0b3",
"v3.0b2",
"v3.0b1",
"v3.0a5",
"v3.0a4",
"v3.0a3",
"v3.0a2",
"v3.0a1",
"v2.4",
"v2.4c1",
"v2.4b2",
"v2.4b1",
"v2.4a3",
"v2.4a2",
"v2.4a1",
"v2.3c2",
"v2.3c1",
"v2.2a3",
"v2.1",
"v2.1c2",
"v2.1c1",
"v2.1b2",
"v2.1b1",
"v2.1a2",
"v2.1a1",
"v2.0",
"v2.0c1",
"v2.0b2",
"v2.0b1",
"v1.6a2",
"v1.6a1",
"v1.5.2",
"v1.5.2c1",
"v1.5.2b2",
"v1.5.2b1",
"v1.5.2a2",
"v1.5.2a1",
"v1.5.1",
"v1.5",
"v1.5b2",
"v1.5b1",
"v1.5a4",
"v1.5a3",
"v1.5a2",
"v1.5a1",
"v1.4",
"v1.4b3",
"v1.4b2",
"v1.4b1",
"v1.3",
"v1.3b1",
"v1.2",
"v1.2b4",
"v1.2b3",
"v1.2b2",
"v1.2b1",
"v1.1.1",
"v1.1",
"v1.0.2",
"v1.0.1",
"v0.9.9",
"v0.9.8"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26116.json"
}
}
],
"modified": "2026-10-24T10:31:02.331633198Z",
"provider": "osv",
"references": [
"https://cert-portal.siemens.com/productcert/html/ssa-398330.html",
"https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BW4GCLQISJCOEGQNIMVUZDQMIY6RR6CC/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HDQ2THWU4GPV4Y5H5WW5PFMSWXL2CRFD/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JWMAVY4T4257AZHTF2RZJKNJNSJFY24O/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OXI72HIHMXCQFWTULUXDG7VDA2BCYL4Y/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QOX7DGMMWWL6POCRYGAUCISOLR2IG3XV/",
"https://lists.debian.org/debian-lts-announce/2020/11/msg00032.html",
"https://security.gentoo.org/glsa/202101-18",
"https://security.netapp.com/advisory/ntap-20201023-0001/",
"https://usn.ubuntu.com/4581-1/",
"https://bugs.python.org/issue39603",
"https://python-security.readthedocs.io/vuln/http-header-injection-method.html",
"https://www.oracle.com/security-alerts/cpuoct2021.html"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:canonical:ubuntu_linux:12.04:*:*:*:-:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*",
"cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*"
],
"vendor_product": "canonical:ubuntu_linux",
"extracted_events": [
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"introduced": "12.04"
},
{
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},
{
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},
{
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},
{
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},
{
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{
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],
"source": "CPE_STRING"
}
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},
{
"cpes": [
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],
"vendor_product": "debian:debian_linux",
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},
{
"cpes": [
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"cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*"
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{
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{
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{
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{
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}
],
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}
]
},
{
"cpes": [
"cpe:2.3:o:opensuse:leap:15.1:*:*:*:*:*:*:*"
],
"vendor_product": "opensuse:leap",
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{
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{
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}
],
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}
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},
{
"cpes": [
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],
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{
"range": [
{
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{
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}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2020-26116",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 439995,
"published_at": "2020-09-27T04:15:11.587+00:00"
}