This vulnerability arises when the l2ald process fails to release memory after it has completed its task, leading to a memory‑leak condition identified as CWE‑401. An unauthenticated attacker on the adjacent LAN can craft packets that trigger the flaw, causing the affected device to consume growing amounts of memory and ultimately become unavailable. The denial of service can impact all routing, forwarding and management functions, rendering the Juniper device inoperable until the system is restarted or the memory is freed.

The flaw exists in Juniper Networks Junos OS and Junos OS Evolved devices running any release before the patches listed below. For Junos OS the vulnerability is mitigated in releases 23.4R2‑S8.13, 24.2R2‑S5.5, 24.4R2‑S5, 25.2R2‑S2, 25.4R1‑S3, 25.4R2, 26.2R1‑S2, 26.2R2, 26.4R1 and all subsequent releases. For Junos OS Evolved the issue is fixed in releases 23.4R2‑S8.11‑EVO, 24.2R2‑S5.6‑EVO, 24.4R2‑S5‑EVO, 25.2R2‑S2‑EVO, 25.2X100‑D35‑EVO, 25.4R1‑S3‑EVO, 25.4R2‑EVO, 25.4X300‑D40‑EVO, 26.2R1‑S2‑EVO, 26.2R2‑EVO, 26.4R1‑EVO and all later releases.

The CVSS score of 7.1 classifies the problem as high severity. No EPSS value is published, so the probability of exploitation is unknown, but the attack is feasible to an adjacent attacker with the ability to send crafted packets to a device that has static MAC‑IP enabled. The flaw is not listed in the CISA KEV catalog, indicating there are no recorded widespread exploits at this time. Nonetheless, the denial of service that can be achieved by exhausting device memory is significant for network availability and operational continuity.