A Missing Release of Memory after Effective Lifetime vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause a memory leak ultimately leading to a Denial of Service (DoS).
In an EVPN-MPLS scenario, routes learned from remote multi-homed Provider Edge (PE) devices are programmed as ESI routes. Due to a logic issue in the l2ald memory management, memory allocated for these routes is not released when there is churn for these routes. As a result, memory leaks in the l2ald process which will ultimately lead to a crash and restart of l2ald.
Use the following command to monitor the memory consumption by l2ald:
user@device> show system process extensive | match "PID|l2ald"
This issue affects:
Junos OS:
* all versions before 22.4R3-S5,
* 23.2 versions before 23.2R2-S3,
* 23.4 versions before 23.4R2-S4,
* 24.2 versions before 24.2R2;
Junos OS Evolved:
* all versions before 22.4R3-S5-EVO,
* 23.2 versions before 23.2R2-S3-EVO,
* 23.4 versions before 23.4R2-S4-EVO,
* 24.2 versions before 24.2R2-EVO.
References
| Link | Resource |
|---|---|
| https://kb.juniper.net/JSA107819 | Vendor Advisory |
Configurations
Configuration 1 (hide)
|
Configuration 2 (hide)
|
History
26 Oct 2026, 22:10
| Type | Values Removed | Values Added |
|---|---|---|
| Summary |
|
Information
Published : 2026-04-09 22:16
Updated : 2026-10-26 22:10
NVD link : CVE-2026-33780
Mitre link : CVE-2026-33780
CVE.ORG link : CVE-2026-33780
JSON object : View
Products Affected
juniper
- junos
- junos_os_evolved
CWE
CWE-401
Missing Release of Memory after Effective Lifetime