CVE-2023-31130: C-Ares Project C-Ares

Medium severity, CVSS 6.4. EPSS: 0.4% chance of exploitation in the next 30 days.

c-ares is an asynchronous resolver library. ares_inet_net_pton() is vulnerable to a buffer underflow for certain ipv6 addresses, in particular "0::00:00:00/2" was found to cause an issue. C-ares only uses this function internally for configuration purposes which would require an administrator to configure such an address via ares_set_sortlist(). However, users may externally use ares_inet_net_pton() for other purposes and thus be vulnerable to more severe issues. This issue has been fixed in 1.19.1.

Affected products

• C-Ares Project C-Ares: before 1.19.1 (fixed in 1.19.1)
• Debian Debian Linux: version 10.0 only; version 11.0 only
• Fedoraproject Fedora: version 37 only; version 38 only

Published 2023-05-25. Last modified 2026-06-17.