python-socketio — security advisory
python-socketio is a Python implementation of the Socket.IO realtime client and server. The python-socketio server stores binary `EVENT` and `ACK` messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. Prior to version 5.16.4, an attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time. Version 5.16.4 takes the following measures to address this issue: Binary packets are only accepted from authenticated clients and, when a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.
- Products
- python-socketio
- Affected versions
- 5.11.2-1, 5.11.2-1.1, 5.12.1-1, 5.13.0-1, 5.16.0-1, 5.17.0-1, 5.7.2-2
- Fixed versions
- 5.17.0-1
- CVEs
- CVE-2026-48804
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 28 Oct 2026, 10:41 UTC · Revision 1
Source evidence
python-socketio is a Python implementation of the Socket.IO realtime client and server. The python-socketio server stores binary `EVENT` and `ACK` messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. Prior to version 5.16.4, an attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time. Version 5.16.4 takes the following measures to address this issue: Binary packets are only accepted from authenticated clients and, when a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.
osv:DEBIAN-CVE-2026-48804
python-socketio
Fixed versions: Not specified
python-socketio
Fixed versions: Not specified
python-socketio
Fixed versions: 5.17.0-1
Complete source record
{
"id": "6df118f71b110ad8fad556d61b2d57371a338bc471064300f98a456fd93aa99a",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-48804",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-48804",
"summary": "python-socketio is a Python implementation of the Socket.IO realtime client and server. The python-socketio server stores binary `EVENT` and `ACK` messages in memory while it waits to receive their binary attachments. Once all the attachments are received, these messages are then processed. Prior to version 5.16.4, an attacker can submit a binary message and intentionally omit sending one or more of its attachments to cause the message along with the partial list of received attachments to stay in memory for a long time. Version 5.16.4 takes the following measures to address this issue: Binary packets are only accepted from authenticated clients and, when a client disconnects, the server checks if there is a partial binary message being held for the client and deletes it.",
"evidence": "osv:DEBIAN-CVE-2026-48804",
"products": [
{
"name": {
"value": "python-socketio",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.11.2-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.11.2-1.1",
"evidence": "/affected/0/versions"
},
{
"value": "5.12.1-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.13.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.16.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.17.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.7.2-2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
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"evidence": "/affected/1/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "5.12.1-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.13.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.16.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.17.0-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "python-socketio",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "5.17.0-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "5.12.1-1",
"evidence": "/affected/2/versions"
},
{
"value": "5.13.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "5.16.0-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-48804",
"aliases": [
"DEBIAN-CVE-2026-48804"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "python-socketio",
"purl": "pkg:deb/debian/python-socketio?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"5.11.2-1",
"5.11.2-1.1",
"5.12.1-1",
"5.13.0-1",
"5.16.0-1",
"5.17.0-1",
"5.7.2-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48804.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "python-socketio",
"purl": "pkg:deb/debian/python-socketio?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"5.12.1-1",
"5.13.0-1",
"5.16.0-1",
"5.17.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48804.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "5.17.0-1"
}
]
}
],
"package": {
"name": "python-socketio",
"purl": "pkg:deb/debian/python-socketio?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"5.12.1-1",
"5.13.0-1",
"5.16.0-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-48804.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-09T05:00:06.899687435Z",
"provider": "osv",
"upstream": [
"CVE-2026-48804"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-48804"
]
},
"related_cves": [
{
"value": "CVE-2026-48804",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 108704,
"published_at": "2026-08-11T20:17:42.58+00:00"
}