CVE-2025-48945

high

Description

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.

References

https://github.com/saghul/pycares/security/advisories/GHSA-5qpg-rh4j-qp35

https://github.com/saghul/pycares/releases/tag/v4.9.0

https://github.com/saghul/pycares/commit/ebfd7d71eb8e74bc1057a361ea79a5906db510d4

https://github.com/aio-libs/aiodns/releases/tag/v3.5.0

https://github.com/aio-libs/aiodns/commit/f259a6e3650555157af53ac2b39f2ff545321d55

Details

Source: Mitre, NVD

Published: 2025-06-20

Updated: 2025-06-23

Risk Information

CVSS v2

Base Score: 5.6

Vector: CVSS2#AV:N/AC:H/Au:S/C:N/I:P/A:C

Severity: Medium

CVSS v3

Base Score: 5.9

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H

Severity: Medium

CVSS v4

Base Score: 8.2

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

Severity: High

EPSS

EPSS: 0.00045