CVE-2021-26690: Apache HTTP Server

High severity, CVSS 7.5. EPSS: 65.3% chance of exploitation in the next 30 days.

Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can cause a NULL pointer dereference and crash, leading to a possible Denial Of Service

Affected products

• Apache HTTP Server: from 2.4.0, up to and including 2.4.46
• Debian Debian Linux: version 9.0 only; version 10.0 only
• Fedoraproject Fedora: version 34 only; version 35 only
• Oracle Enterprise Manager Ops Center: version 12.4.0.0 only
• Oracle Instantis Enterprisetrack: version 17.1 only; version 17.2 only; version 17.3 only
• Oracle ZFS Storage Appliance Kit: version 8.8 only

Published 2021-06-10. Last modified 2026-06-17.