CVE-2026-33780Junos OS and Junos OS Evolved: In an EVPN-MPLS scenario churn of ESI routes causes a memory leak in l2ald
Updated under an hour ago ()
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It affects Juniper Networks Junos OS and 3 other products. Add what you run to find out whether that includes you.
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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.
- CVSS
- 6.5 MEDIUM (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weakness (CWE)
- CWE-401
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- juniper
- NVD analysis
- Analyzed
- Record last updated
- Apr 13, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Juniper Networks Junos OS juniper_networks:junos_os (from the name) | before 22.4R3-S5; from 23.2 before 23.2R2-S3; from 23.4 before 23.4R2-S4; from 24.2 before 24.2R2 | CNA record |
Juniper Networks Junos OS Evolved juniper_networks:junos_os_evolved (from the name) | from all version prior to before 22.4R3-S5-EVO; from 23.2 before 23.2R2-S3-EVO; from 23.4 before 23.4R2-S4-EVO; from 24.2 before 24.2R2-EVO | CNA record |
juniper junos juniper:junos | before 22.4; 22.4; 22.4; 22.4; 22.4; 22.4; 22.4; 22.4; and 24 more ranges | NVD |
juniper junos_os_evolved juniper:junos_os_evolved | before 22.4; 22.4; 22.4; 22.4; 22.4; 22.4; 22.4; 22.4; and 23 more ranges | NVD |
References
- https://kb.juniper.net/JSA107819vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.