CVE-2025-48945: Aio-Libs Aiodns

High severity, CVSS 8.2. EPSS: 0.5% chance of exploitation in the next 30 days.

pycares is a Python module which provides an interface to c-ares. c-ares is a C library that performs DNS requests and name resolutions asynchronously. Prior to version 4.9.0, pycares is vulnerable to a use-after-free condition that occurs when a Channel object is garbage collected while DNS queries are still pending. This results in a fatal Python error and interpreter crash. The vulnerability has been fixed in pycares 4.9.0 by implementing a safe channel destruction mechanism.

Affected products

• Aio-Libs Aiodns: before 4.9.0 (fixed in 4.9.0)

Published 2025-06-20. Last modified 2026-06-17.