| Name | CVE-2025-48945 |
| 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. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| pycares (PTS) | bullseye | 3.1.1-1 | vulnerable |
| bookworm | 4.3.0-2 | vulnerable |
| trixie, sid | 4.4.0-2 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| pycares | source | (unstable) | (unfixed) | | | |
Notes
[bookworm] - pycares <no-dsa> (Minor issue, too intrusive to backport)
[bullseye] - pycares <postponed> (Minor issue; can be fixed in next update)
https://github.com/saghul/pycares/security/advisories/GHSA-5qpg-rh4j-qp35
Fixed by: https://github.com/saghul/pycares/commit/ebfd7d71eb8e74bc1057a361ea79a5906db510d4 (v4.9.0)