CVE-2023-28320: Apple macOS

Medium severity, CVSS 5.9. EPSS: 2.7% chance of exploitation in the next 30 days.

A denial of service vulnerability exists in curl <v8.1.0 in the way libcurl provides several different backends for resolving host names, selected at build time. If it is built to use the synchronous resolver, it allows name resolves to time-out slow operations using `alarm()` and `siglongjmp()`. When doing this, libcurl used a global buffer that was not mutex protected and a multi-threaded application might therefore crash or otherwise misbehave.

Affected products

• Apple macOS: from 11.0, before 11.7.9 (fixed in 11.7.9); from 12.0, before 12.6.8 (fixed in 12.6.8); from 13.0, before 13.5 (fixed in 13.5)
• Haxx Curl: before 8.1.0 (fixed in 8.1.0)
• Netapp Clustered Data Ontap: affected versions not specified
• Netapp h300s Firmware: affected versions not specified
• Netapp h410s Firmware: affected versions not specified
• Netapp h500s Firmware: affected versions not specified
• Netapp h700s Firmware: affected versions not specified
• Netapp Ontap Antivirus Connector: affected versions not specified

Published 2023-05-26. Last modified 2026-06-17.