CVE-2025-48945CWE-416

pycares has a Use-After-Free Vulnerability

High · published June 20, 2025

CVSS v4.0
8.2
EPSS
0%
Percentile
40.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.2 · HIGH
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
EPSS
0.00484 · 40.8th percentile
Weakness
CWE-416 · Use After Free
Published
2025-06-20T19:14Z
EPSS history
Timeline
  • 20 JUN 19:14Z
    pycares has a Use-After-Free Vulnerability
    cvelistv5