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CVE PROGRAM SOURCE RECORD7.1 High

CVE-2026-33780

Junos OS and Junos OS Evolved: In an EVPN-MPLS scenario churn of ESI routes causes a memory leak in l2ald

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Juniper Networks Junos OS

Default version status: unaffected

  • 0 to < 22.4R3-S5affected
  • 23.2 to < 23.2R2-S3affected
  • 23.4 to < 23.4R2-S4affected
  • 24.2 to < 24.2R2affected

Juniper Networks Junos OS Evolved

Default version status: unaffected

  • all version prior to to < 22.4R3-S5-EVOaffected
  • 23.2 to < 23.2R2-S3-EVOaffected
  • 23.4 to < 23.4R2-S4-EVOaffected
  • 24.2 to < 24.2R2-EVOaffected

References