USN-7927-3
Unknown
USN-7927-3: urllib3 regression
Canonical (Ubuntu)
Released: January 13, 2026
Updated: January 15, 2026
Restart Required
Description
USN-7927-1 fixed vulnerabilities in urllib3. The update for CVE-2025-66471
introduced a regression in urllib3 when decompressing zstd data. This
update fixes the problem.
We apologize for the inconvenience.
Original advisory details:
Illia Volochii discovered that urllib3 did not limit the steps in a
decompression chain. An attacker could possibly use this issue to cause
urllib3 to use excessive resources, causing a denial of service.
(CVE-2025-66418)
Rui Xi discovered that urllib3 incorrectly handled highly compressed data.
An attacker could possibly use this issue to cause urllib3 to use
excessive resources, causing a denial of service. This issue only affected
Ubuntu 24.04 LTS, Ubuntu 25.04, and Ubuntu 25.10. (CVE-2025-66471)
For the brotli encoding, the fix for CVE-2025-66471 requires an additional
security update in the brotli package.
Fixed Vulnerabilities 1
Dec 05, 2025
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.…
Quick Info
Patch ID:
USN-7927-3
Vendor:
Canonical (Ubuntu)
Severity:
Unknown
CVEs Fixed:
1
Restart:
Required
Vendor
Canonical (Ubuntu)Additional Info
action:
usn id:
USN-7927-3
summary:
USN-7927-1 introduced a regression in urllib3
usn number:
7927-3
instructions:
In general, a standard system update will make all the necessary changes.