CVE-2025-48945 HIGH

CVE-2025-48945: pycares has a Use-After-Free Vulnerability

Vendor Aio-Libs
Product aiodns
Weakness CWE-416
Published June 20, 2025
Last update June 20, 2025

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

June 20, 2025 CVE published
June 20, 2025 Record updated