Race condition in Junos OS - CVE-2026-57030
Published: July 8, 2026
Vulnerability identifier: #VU137151
CSH Severity: Medium
CVSS v4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-57030
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a race condition in the packet forwarding engine (PFE) when removing flow sessions during stateful traffic processing. A remote attacker can send network traffic to cause a denial of service.
The issue can cause flow sessions to remain with unexpectedly large timeout values, leading to accumulation of invalidated sessions; under some conditions forwarding stops and manual recovery with a reboot may be required, or flowd may core and trigger an automatic reboot.
Affected software
Junos OS
How to mitigate CVE-2026-57030
Install security update from vendor's website.
Junos OS - addressed in versions 24.2R2-S3, 24.4R2-S1, 25.2R1-S2, 25.2R2, 25.4R1