DEBIAN-CVE-2025-66471
urllib3 is a user-friendly HTTP client library for Python. Starting in version 1.0 and prior to 2.6.0, the Streaming API improperly handles highly compressed data. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. When streaming a compressed response, urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). The library must read compressed data from the network and decompress it until the requested chunk size is met. Any resulting decompressed data that exceeds the requested amount is held in an internal buffer for the next read operation. The decompression logic could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This can result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data.
DEBIAN-CVE-2025-66471
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:DEBIAN-CVE-2025-66471
python-urllib3
Source reference: /affected/0/package/name
- Affected versions
- 1.26.12-1
Source reference:
/affected/0/versions1.26.12-1+deb12u1Source reference:
/affected/0/versions1.26.12-1+deb12u2Source reference:
/affected/0/versions1.26.12-1+deb12u3Source reference:
/affected/0/versions1.26.12-1+deb12u4Source reference:
/affected/0/versions1.26.16-1Source reference:
/affected/0/versions1.26.17-1Source reference:
/affected/0/versions1.26.18-1Source reference:
/affected/0/versions1.26.18-2Source reference:
/affected/0/versions2.0.7-1Source reference:
/affected/0/versions2.0.7-2Source reference:
/affected/0/versions2.2.3-1Source reference:
/affected/0/versions2.2.3-2Source reference:
/affected/0/versions2.2.3-3Source reference:
/affected/0/versions2.2.3-4Source reference:
/affected/0/versions2.3.0-1Source reference:
/affected/0/versions2.3.0-2Source reference:
/affected/0/versions2.3.0-3Source reference:
/affected/0/versions2.5.0-1Source reference:
/affected/0/versions2.5.0-1.1Source reference:
/affected/0/versions2.5.0-2Source reference:
/affected/0/versions2.6.3-1Source reference:
/affected/0/versions2.6.3-2Source reference:
/affected/0/versions2.7.0-1Source reference:
/affected/0/versions2.7.0-2Source reference:
/affected/0/versions2.7.0-3Source reference:
/affected/0/versions2.8.0-1Source reference:
/affected/0/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
python-urllib3
Source reference: /affected/1/package/name
- Affected versions
- 2.3.0-3
Source reference:
/affected/1/versions2.3.0-3+deb13u1Source reference:
/affected/1/versions2.3.0-3+deb13u2Source reference:
/affected/1/versions2.5.0-1Source reference:
/affected/1/versions2.5.0-1.1Source reference:
/affected/1/versions2.5.0-2Source reference:
/affected/1/versions2.6.3-1Source reference:
/affected/1/versions2.6.3-2Source reference:
/affected/1/versions2.7.0-1Source reference:
/affected/1/versions2.7.0-2Source reference:
/affected/1/versions2.7.0-3Source reference:
/affected/1/versions2.8.0-1Source reference:
/affected/1/versions - Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
python-urllib3
Source reference: /affected/2/package/name
- Affected versions
- 2.3.0-3
Source reference:
/affected/2/versions2.5.0-1Source reference:
/affected/2/versions2.5.0-1.1Source reference:
/affected/2/versions2.5.0-2Source reference:
/affected/2/versions - Fixed versions
- 2.6.3-1
Source reference:
/affected/2/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"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"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-66471.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"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-66471.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2.6.3-1"
}
]
}
],
"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"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-66471.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
]Publisher severity
No explicit severity was provided.
- Event
- #18761 · Revision 1
- Added to Heist Feed
- Publisher date