vulnerability
Ubuntu: USN-5812-1 (CVE-2021-33503): urllib3 vulnerability
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 5 | (AV:N/AC:L/Au:N/C:N/I:N/A:P) | Jun 18, 2021 | Jan 20, 2023 | Mar 27, 2026 |
Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:P)
Published
Jun 18, 2021
Added
Jan 20, 2023
Modified
Mar 27, 2026
Description
An issue was discovered in urllib3 before 1.26.5. When provided with a URL containing many @ characters in the authority component, the authority regular expression exhibits catastrophic backtracking, causing a denial of service if a URL were passed as a parameter or redirected to via an HTTP redirect.
Solution
ubuntu-upgrade-python3-urllib3
Rapid7 Labs
2026 Global Threat Landscape Report
The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.