HighFix available
python-urllib3 — security advisory
urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.
- Products
- python-urllib3
- Affected versions
- 1.26.12-1, 1.26.12-1+deb12u1, 1.26.12-1+deb12u2, 1.26.12-1+deb12u3, 1.26.12-1+deb12u4, 1.26.16-1, 1.26.17-1, 1.26.18-1, 1.26.18-2, 2.0.7-1, 2.0.7-2, 2.2.3-1, 2.2.3-2, 2.2.3-3, 2.2.3-4, 2.3.0-1, 2.3.0-2, 2.3.0-3, 2.3.0-3+deb13u1, 2.3.0-3+deb13u2, 2.5.0-1, 2.5.0-1.1, 2.5.0-2, 2.6.3-1, 2.6.3-2, 2.7.0-1, 2.7.0-2, 2.7.0-3, 2.8.0-1, 2.8.0-2
- Fixed versions
- 2.8.0-1
- CVEs
- CVE-2026-97689
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 30 Oct 2026, 11:50 UTC · Revision 1
Source evidence
urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.
osv:DEBIAN-CVE-2026-97689
python-urllib3
Fixed versions: Not specified
python-urllib3
Fixed versions: Not specified
python-urllib3
Fixed versions: 2.8.0-1
Complete source record
{
"id": "4e81587144695073bd14b4e3bbcef0df486562c0a2a5cdce399d5efd1883d713",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-97689",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-97689",
"summary": "urllib3 is an HTTP client library for Python. From 1.10.3 until 2.8.0, the HTTPResponse.read_chunked and HTTPResponse.stream methods can allocate unbounded memory because the streaming chunk parser buffers the chunk-size field until newline or EOF without a length bound. The trigger is that a malicious server returns Transfer-Encoding: chunked followed by a very long run of bytes without a newline. The attack mechanism is that a malicious HTTP server sends a very long unterminated chunk-size line. The impact is that unbounded memory allocation can exhaust the client process. This issue is fixed in version 2.8.0.",
"evidence": "osv:DEBIAN-CVE-2026-97689",
"products": [
{
"name": {
"value": "python-urllib3",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "1.26.12-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.12-1+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.12-1+deb12u2",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.12-1+deb12u3",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.12-1+deb12u4",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.16-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.17-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.18-1",
"evidence": "/affected/0/versions"
},
{
"value": "1.26.18-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.0.7-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.0.7-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.3-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.3-3",
"evidence": "/affected/0/versions"
},
{
"value": "2.2.3-4",
"evidence": "/affected/0/versions"
},
{
"value": "2.3.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.3.0-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.3.0-3",
"evidence": "/affected/0/versions"
},
{
"value": "2.5.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.5.0-1.1",
"evidence": "/affected/0/versions"
},
{
"value": "2.5.0-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.6.3-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.7.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.7.0-2",
"evidence": "/affected/0/versions"
},
{
"value": "2.7.0-3",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.0-1",
"evidence": "/affected/0/versions"
},
{
"value": "2.8.0-2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "python-urllib3",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "2.3.0-3",
"evidence": "/affected/1/versions"
},
{
"value": "2.3.0-3+deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "2.3.0-3+deb13u2",
"evidence": "/affected/1/versions"
},
{
"value": "2.5.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.5.0-1.1",
"evidence": "/affected/1/versions"
},
{
"value": "2.5.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "2.6.3-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.6.3-2",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.0-2",
"evidence": "/affected/1/versions"
},
{
"value": "2.7.0-3",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.0-1",
"evidence": "/affected/1/versions"
},
{
"value": "2.8.0-2",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "python-urllib3",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2.8.0-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": [
{
"value": "2.3.0-3",
"evidence": "/affected/2/versions"
},
{
"value": "2.5.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.5.0-1.1",
"evidence": "/affected/2/versions"
},
{
"value": "2.5.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.6.3-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.6.3-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.7.0-1",
"evidence": "/affected/2/versions"
},
{
"value": "2.7.0-2",
"evidence": "/affected/2/versions"
},
{
"value": "2.7.0-3",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-97689",
"aliases": [
"DEBIAN-CVE-2026-97689"
],
"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-urllib3",
"purl": "pkg:deb/debian/python-urllib3?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"1.26.12-1",
"1.26.12-1+deb12u1",
"1.26.12-1+deb12u2",
"1.26.12-1+deb12u3",
"1.26.12-1+deb12u4",
"1.26.16-1",
"1.26.17-1",
"1.26.18-1",
"1.26.18-2",
"2.0.7-1",
"2.0.7-2",
"2.2.3-1",
"2.2.3-2",
"2.2.3-3",
"2.2.3-4",
"2.3.0-1",
"2.3.0-2",
"2.3.0-3",
"2.5.0-1",
"2.5.0-1.1",
"2.5.0-2",
"2.6.3-1",
"2.6.3-2",
"2.7.0-1",
"2.7.0-2",
"2.7.0-3",
"2.8.0-1",
"2.8.0-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-97689.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "python-urllib3",
"purl": "pkg:deb/debian/python-urllib3?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"2.3.0-3",
"2.3.0-3+deb13u1",
"2.3.0-3+deb13u2",
"2.5.0-1",
"2.5.0-1.1",
"2.5.0-2",
"2.6.3-1",
"2.6.3-2",
"2.7.0-1",
"2.7.0-2",
"2.7.0-3",
"2.8.0-1",
"2.8.0-2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-97689.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.8.0-1"
}
]
}
],
"package": {
"name": "python-urllib3",
"purl": "pkg:deb/debian/python-urllib3?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2.3.0-3",
"2.5.0-1",
"2.5.0-1.1",
"2.5.0-2",
"2.6.3-1",
"2.6.3-2",
"2.7.0-1",
"2.7.0-2",
"2.7.0-3"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-97689.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-14T10:00:39.855830729Z",
"provider": "osv",
"upstream": [
"CVE-2026-97689"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-97689"
]
},
"related_cves": [
{
"value": "CVE-2026-97689",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 315378,
"published_at": "2026-09-29T16:17:18.837+00:00"
}