Memory leak in Junos OS - CVE-2026-57027
Published: July 8, 2026
Vulnerability identifier: #VU137131
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-57027
CWE-ID: CWE-401
Exploitation vector: Adjecent network
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to missing release of memory after effective lifetime error in the packet forwarding engine (pfe). A remote non-authenticated attacker can cause a Denial-of-Service (DoS).
When sFlow is configured in a Virtual Chassis (VC) scenario with EX4100 Series or EX4400 Series devices, multicast traffic which is received on 1 VC member and sent out on another member leads to a memory leak and ultimately an FPC crash and restart.
Affected software
Junos OS
How to mitigate CVE-2026-57027
Install updates from vendor's website.
Junos OS - addressed in versions 23.2R2-S7, 23.4R2-S7, 24.2R2-S4, 24.4R2, 25.2R1