Instituto Nacional de ciberseguridad. Sección Incibe
Instituto Nacional de Ciberseguridad. Sección INCIBE-CERT

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CVE-2026-33780

Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
09/04/2026
Last modified:
17/04/2026

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).<br /> <br /> <br /> <br /> 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.<br /> <br /> Use the following command to monitor the memory consumption by l2ald:<br /> <br /> user@device&gt; show system process extensive | match "PID|l2ald" <br /> <br /> <br /> <br /> This issue affects:<br /> <br /> Junos OS:<br /> <br /> <br /> <br /> * all versions before 22.4R3-S5,<br /> * 23.2 versions before 23.2R2-S3,<br /> * 23.4 versions before 23.4R2-S4,<br /> * 24.2 versions before 24.2R2;<br /> <br /> <br /> <br /> <br /> Junos OS Evolved:<br /> <br /> <br /> <br /> * all versions before 22.4R3-S5-EVO,<br /> * 23.2 versions before 23.2R2-S3-EVO,<br /> * 23.4 versions before 23.4R2-S4-EVO,<br /> * 24.2 versions before 24.2R2-EVO.

Impact

Vector 4.0
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M CVSS v4.0 Severity and Metrics:

Base Score: 7.10 HIGH
Vector: CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Attack Requirements (AT): None
Privileges Required (PR): None
User Interaction (UI): None
Confidentiality (VC): None
Integrity (VI): None
Availability (VA): High
Confidentiality (SC): None
Integrity (SI): None
Availability (SA): Low
Automatable (AU): Yes
Vulnerability Response Effort (RE): Moderate

Base Score 4.0
7.10
Severity 4.0
HIGH
Vector 3.x
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 6.50 MEDIUM
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Adjacent
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
6.50
Severity 3.x
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* 22.4 (excluding)
cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r3-s3:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:22.4:r3-s4:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:*
cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:*

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools