HighFix available
pymongo — security advisory
PyMongo's connection string parsing decodes percent-encoded characters in the host portion before the host list is separated on its delimiters. When an application places a hostname value supplied by an unauthenticated party into a connection string, that party may cause additional servers of their choosing to be added to the application's database client. The application may then send its authentication exchange and database operations to one of those servers, which can observe limited information and return altered results.
- Products
- pymongo
- Affected versions
- 3.11.0-1, 3.11.0-1+deb12u1, 4.10.1-1, 4.10.1-2, 4.10.1-3, 4.10.1-4, 4.10.1-5, 4.10.1-6, 4.15.3-1, 4.15.3-2, 4.15.4-1, 4.15.4-2, 4.15.5-1, 4.16.0-1, 4.17.0-1, 4.18.1-1, 4.18.2-1, 4.7.3-1, 4.7.3-2
- Fixed versions
- 4.18.2-1
- CVEs
- CVE-2026-96748
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 06:34 UTC · Revision 1
Source evidence
PyMongo's connection string parsing decodes percent-encoded characters in the host portion before the host list is separated on its delimiters. When an application places a hostname value supplied by an unauthenticated party into a connection string, that party may cause additional servers of their choosing to be added to the application's database client. The application may then send its authentication exchange and database operations to one of those servers, which can observe limited information and return altered results.
osv:DEBIAN-CVE-2026-96748
pymongo
Fixed versions: Not specified
pymongo
Fixed versions: Not specified
pymongo
Fixed versions: 4.18.2-1
Complete source record
{
"id": "bdbaa821044cd85f2a8968c1fb1690f6ec667b915f54bb33739a7faf03135e3f",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-96748",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-96748",
"summary": "PyMongo's connection string parsing decodes percent-encoded characters in the host portion before the host list is separated on its delimiters. When an application places a hostname value supplied by an unauthenticated party into a connection string, that party may cause additional servers of their choosing to be added to the application's database client. The application may then send its authentication exchange and database operations to one of those servers, which can observe limited information and return altered results.",
"evidence": "osv:DEBIAN-CVE-2026-96748",
"products": [
{
"name": {
"value": "pymongo",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "3.11.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "3.11.0-1+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.1-2",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.1-3",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.1-4",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.1-5",
"evidence": "/affected/0/versions"
},
{
"value": "4.10.1-6",
"evidence": "/affected/0/versions"
},
{
"value": "4.15.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.15.3-2",
"evidence": "/affected/0/versions"
},
{
"value": "4.15.4-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.15.4-2",
"evidence": "/affected/0/versions"
},
{
"value": "4.15.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.16.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.17.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.18.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.18.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.7.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "4.7.3-2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "pymongo",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.10.1-6",
"evidence": "/affected/1/versions"
},
{
"value": "4.15.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.15.3-2",
"evidence": "/affected/1/versions"
},
{
"value": "4.15.4-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.15.4-2",
"evidence": "/affected/1/versions"
},
{
"value": "4.15.5-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.16.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.17.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.18.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "4.18.2-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "pymongo",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "4.18.2-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "4.10.1-6",
"evidence": "/affected/2/versions"
},
{
"value": "4.15.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.15.3-2",
"evidence": "/affected/2/versions"
},
{
"value": "4.15.4-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.15.4-2",
"evidence": "/affected/2/versions"
},
{
"value": "4.15.5-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.16.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.17.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "4.18.1-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-96748",
"aliases": [
"DEBIAN-CVE-2026-96748"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pymongo",
"purl": "pkg:deb/debian/pymongo?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"3.11.0-1",
"3.11.0-1+deb12u1",
"4.10.1-1",
"4.10.1-2",
"4.10.1-3",
"4.10.1-4",
"4.10.1-5",
"4.10.1-6",
"4.15.3-1",
"4.15.3-2",
"4.15.4-1",
"4.15.4-2",
"4.15.5-1",
"4.16.0-1",
"4.17.0-1",
"4.18.1-1",
"4.18.2-1",
"4.7.3-1",
"4.7.3-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-96748.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "pymongo",
"purl": "pkg:deb/debian/pymongo?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"4.10.1-6",
"4.15.3-1",
"4.15.3-2",
"4.15.4-1",
"4.15.4-2",
"4.15.5-1",
"4.16.0-1",
"4.17.0-1",
"4.18.1-1",
"4.18.2-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-96748.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "4.18.2-1"
}
]
}
],
"package": {
"name": "pymongo",
"purl": "pkg:deb/debian/pymongo?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"4.10.1-6",
"4.15.3-1",
"4.15.3-2",
"4.15.4-1",
"4.15.4-2",
"4.15.5-1",
"4.16.0-1",
"4.17.0-1",
"4.18.1-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-96748.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-12T11:00:45.656306559Z",
"provider": "osv",
"upstream": [
"CVE-2026-96748"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-96748"
]
},
"related_cves": [
{
"value": "CVE-2026-96748",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 299783,
"published_at": "2026-09-24T19:17:20.813+00:00"
}