CVE-2026-57021
Junos OS: SRX Series: If VPN compliance-check is configured an attacker can cause http-gk process crash
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Junos OS: SRX Series: If VPN compliance-check is configured an attacker can cause http-gk process crash
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.
- Record
CVE-2026-57021- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/AU:Y/R:A/RE:M - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
EUVDEUVD-2026-42708
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.
- Record
EUVD-2026-42708- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/AU:Y/R:A/RE:M - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-h2m8-76wp-v324
An Out-of-bounds Write vulnerability in the http-gatekeeper (http-gk) of Juniper Networks Junos...
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.
- Record
GHSA-h2m8-76wp-v324- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:M/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-57021- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:M/U:X - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L - Weakness
- CWE-787
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-57021 is a medium vulnerability (CVSS 6.9) in Juniper Junos, published July 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.47%, the 41st percentile. No source names a fixed version.