Updated: 2025-11-10 00:12:25.998685
Description:
An issue was discovered in Python before 3.11.1. An unnecessary quadratic algorithm exists in one path when processing some inputs to the IDNA (RFC 3490) decoder, such that a crafted, unreasonably long name being presented to the decoder could lead to a CPU denial of service. Hostnames are often supplied by remote servers that could be controlled by a malicious actor; in such a scenario, they could trigger excessive CPU consumption on the client attempting to make use of an attacker-supplied supposed hostname. For example, the attack payload could be placed in the Location header of an HTTP response with status code 302. A fix is planned in 3.11.1, 3.10.9, 3.9.16, 3.8.16, and 3.7.16.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | HIGH | 7.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| Ubuntu 22.04 | python | 3.6 | 7.5 | HIGH | Already Fixed | 2025-07-25 02:04:12 | ||
| Ubuntu 24.04 | python | 2.7 | 7.5 | HIGH | Released | CLSA-2025:1760094135 | 2025-10-10 11:32:54 | |
| Ubuntu 24.04 | python | 3.6 | 7.5 | HIGH | Already Fixed | 2025-07-25 02:04:12 |