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MEDIUM · 5.3

CVE-2026-57021

An Out-of-bounds Write vulnerability in the http-gatekeeper (http-gk) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). ...

Vulnerability Description

An Out-of-bounds Write vulnerability in the http-gatekeeper (http-gk) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). If an SRX Series device is configured for remote-access VPN with pre-logon compliance check, a network-based attacker sending specifically formatted requests can trigger an out of bounds write leading to an http-gk process crash. This crash leads to unavailability of all services depending on the [ system services web-management ] configuration (like J-Web, remote access VPN and firewall authentication) until the process automatically restarts. This issue affects Junos OS on SRX Series: * 23.2 versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S8, * 24.2 versions before 24.2R2-S4, * 24.4 versions before 24.4R2-S4, * 25.2 versions before 25.2R2, * 25.4 versions before 25.4R1-S1, 25.4R2.

CVSS Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW

Affected Products

VendorProductVersions
JuniperJunos23.2
JuniperSrx1500-
JuniperSrx1600-
JuniperSrx2300-
JuniperSrx300-
JuniperSrx320-
JuniperSrx340-
JuniperSrx345-
JuniperSrx380-
JuniperSrx400-
JuniperSrx4100-
JuniperSrx4120-
JuniperSrx4200-
JuniperSrx4300-
JuniperSrx440-
JuniperSrx4600-
JuniperSrx4700-
JuniperSrx5400-
JuniperSrx5600-
JuniperSrx5800-

Related Weaknesses (CWE)

CWE-787

References

FAQ

What is CVE-2026-57021?

CVE-2026-57021 is a vulnerability with a CVSS score of 5.3 (MEDIUM). An Out-of-bounds Write vulnerability in the http-gatekeeper (http-gk) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). ...

How severe is CVE-2026-57021?

CVE-2026-57021 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-57021?

Check the references section above for vendor advisories and patch information. Affected products include: Juniper Junos, Juniper Srx1500, Juniper Srx1600, Juniper Srx2300, Juniper Srx300.