pypy3, python3.11 — security advisory
Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure. NOTE: this is disputed by a third party because the http.server.html documentation page states "Warning: http.server is not recommended for production. It only implements basic security checks."
- Products
- pypy3, python3.11
- Affected versions
- Not specified
- Fixed versions
- 3.11.0~b4-1, 7.3.10+dfsg-1
- CVEs
- CVE-2021-28861
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 16:48 UTC · Revision 1
Source evidence
Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure. NOTE: this is disputed by a third party because the http.server.html documentation page states "Warning: http.server is not recommended for production. It only implements basic security checks."
osv:DEBIAN-CVE-2021-28861
pypy3
Fixed versions: 7.3.10+dfsg-1
pypy3
Fixed versions: 7.3.10+dfsg-1
pypy3
Fixed versions: 7.3.10+dfsg-1
python3.11
Fixed versions: 3.11.0~b4-1
Complete source record
{
"id": "ceaa93d657d1cd15754f53bc5f3ca3d1098f41103a27d6baec1d17bcb87f6ea3",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2021-28861",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2021-28861",
"summary": "Python 3.x through 3.10 has an open redirection vulnerability in lib/http/server.py due to no protection against multiple (/) at the beginning of URI path which may leads to information disclosure. NOTE: this is disputed by a third party because the http.server.html documentation page states \"Warning: http.server is not recommended for production. It only implements basic security checks.\"",
"evidence": "osv:DEBIAN-CVE-2021-28861",
"products": [
{
"name": {
"value": "pypy3",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.3.10+dfsg-1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "pypy3",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.3.10+dfsg-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "pypy3",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "7.3.10+dfsg-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "python3.11",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "3.11.0~b4-1",
"evidence": "/affected/3/ranges"
}
],
"affected_versions": []
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2021-28861",
"aliases": [
"DEBIAN-CVE-2021-28861"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.3.10+dfsg-1"
}
]
}
],
"package": {
"name": "pypy3",
"purl": "pkg:deb/debian/pypy3?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-28861.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.3.10+dfsg-1"
}
]
}
],
"package": {
"name": "pypy3",
"purl": "pkg:deb/debian/pypy3?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-28861.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "7.3.10+dfsg-1"
}
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}
],
"package": {
"name": "pypy3",
"purl": "pkg:deb/debian/pypy3?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-28861.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "3.11.0~b4-1"
}
]
}
],
"package": {
"name": "python3.11",
"purl": "pkg:deb/debian/python3.11?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2021-28861.json"
},
"ecosystem_specific": {
"urgency": "unimportant"
}
}
],
"modified": "2026-10-15T09:47:40.804947687Z",
"provider": "osv",
"upstream": [
"CVE-2021-28861"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2021-28861"
]
},
"related_cves": [
{
"value": "CVE-2021-28861",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 328298,
"published_at": "2022-08-23T01:15:07.617+00:00"
}