CVE-2023-23915: Haxx Curl

Medium severity, CVSS 6.5. EPSS: 0.9% chance of exploitation in the next 30 days.

A cleartext transmission of sensitive information vulnerability exists in curl <v7.88.0 that could cause HSTS functionality to behave incorrectly when multiple URLs are requested in parallel. Using its HSTS support, curl can be instructed to use HTTPS instead of using an insecure clear-text HTTP step even when HTTP is provided in the URL. This HSTS mechanism would however surprisingly fail when multiple transfers are done in parallel as the HSTS cache file gets overwritten by the most recentlycompleted transfer. A later HTTP-only transfer to the earlier host name would then *not* get upgraded properly to HSTS.

Affected products

• Haxx Curl: from 7.77.0, before 7.88.0 (fixed in 7.88.0)
• Netapp Active Iq Unified Manager: affected versions not specified
• Netapp Clustered Data Ontap: version 9.0 only
• 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
• Splunk Universal Forwarder: from 8.2.0, before 8.2.12 (fixed in 8.2.12); from 9.0.0, before 9.0.6 (fixed in 9.0.6); version 9.1.0 only

Published 2023-02-23. Last modified 2026-06-17.