CVE-2026-57021

Name of the Vulnerable Software and Affected Versions Junos OS on SRX Series versions prior to 23.2R2-S7 Junos OS on SRX Series versions prior to 23.4R2-S8 Junos OS on SRX Series versions prior to 24.2R2-S4 Junos OS on SRX Series versions prior to 24.4R2-S4 Junos OS on SRX Series versions prior to 25.2R2 Junos OS on SRX Series versions prior to 25.4R1-S1 Junos OS on SRX Series versions prior to 25.4R2

Description An out-of-bounds write in the http-gatekeeper (http-gk) allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). This occurs when a device is configured for remote-access VPN with pre-logon compliance check. By sending specifically formatted requests, an attacker can trigger a crash of the http-gk process, resulting in the unavailability of services dependent on the system services web-management configuration, such as J-Web, remote access VPN, and firewall authentication, until the process restarts automatically.

Recommendations Update to version 23.2R2-S7 or later. Update to version 23.4R2-S8 or later. Update to version 24.2R2-S4 or later. Update to version 24.4R2-S4 or later. Update to version 25.2R2 or later. Update to version 25.4R1-S1 or later. Update to version 25.4R2 or later.