DEBIAN-CVE-2026-21441

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Source
https://security-tracker.debian.org/tracker/CVE-2026-21441
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21441.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-21441
Upstream
Downstream
Published
2026-01-07T22:15:44.040Z
Modified
2026-01-23T10:15:34.290386Z
Severity
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

urllib3 is an HTTP client library for Python. 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. urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). When using the streaming API, the library decompresses only the necessary bytes, enabling partial content consumption. Starting in version 1.22 and prior to version 2.6.3, for HTTP redirect responses, the library would read the entire response body to drain the connection and decompress the content unnecessarily. This decompression occurred even before any read methods were called, and configured read limits did not restrict the amount of decompressed data. As a result, there was no safeguard against decompression bombs. A malicious server could exploit this to trigger excessive resource consumption on the client. Applications and libraries are affected when they stream content from untrusted sources by setting preload_content=False when they do not disable redirects. Users should upgrade to at least urllib3 v2.6.3, in which the library does not decode content of redirect responses when preload_content=False. If upgrading is not immediately possible, disable redirects by setting redirect=False for requests to untrusted source.

References

Affected packages

Debian:11 / python-urllib3

Package

Name
python-urllib3
Purl
pkg:deb/debian/python-urllib3?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.26.5-1~exp1+deb11u3

Affected versions

1.*

1.26.5-1~exp1
1.26.5-1~exp1+deb11u1
1.26.5-1~exp1+deb11u2

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21441.json"

Debian:12 / python-urllib3

Package

Name
python-urllib3
Purl
pkg:deb/debian/python-urllib3?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
1.26.12-1+deb12u3

Affected versions

1.*

1.26.12-1
1.26.12-1+deb12u1
1.26.12-1+deb12u2

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21441.json"

Debian:13 / python-urllib3

Package

Name
python-urllib3
Purl
pkg:deb/debian/python-urllib3?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.3.0-3+deb13u1

Affected versions

2.*

2.3.0-3

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21441.json"

Debian:14 / python-urllib3

Package

Name
python-urllib3
Purl
pkg:deb/debian/python-urllib3?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
2.5.0-2

Affected versions

2.*

2.3.0-3
2.5.0-1
2.5.0-1.1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-21441.json"