Junos OS and Junos OS Evolved: In an EVPN-MPLS scenario churn of ESI routes causes a memory leak in l2ald
Summary
| CVE | CVE-2026-33780 |
|---|---|
| State | PUBLISHED |
| Assigner | juniper |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-09 22:16:26 UTC |
| Updated | 2026-04-17 17:59:50 UTC |
| 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. |
Risk And Classification
Primary CVSS: v4.0 7.1 HIGH from [email protected]
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:X
EPSS: 0.000200000 probability, percentile 0.051880000 (date 2026-04-20)
Problem Types: CWE-401 | CWE-401 CWE-401 Missing Release of Memory after Effective Lifetime
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.1 | HIGH | 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/E:X/C... |
| 4.0 | CNA | CVSS | 7.1 | HIGH | 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/... |
| 3.1 | [email protected] | Primary | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v4.0 Breakdown
Attack Vector
AdjacentAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
NoneConfidentiality
NoneIntegrity
NoneAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
LowCVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:M/U:X
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Juniper | Junos | All | All | All | All |
| Operating System | Juniper | Junos | 22.4 | - | All | All |
| Operating System | Juniper | Junos | 22.4 | r1 | All | All |
| Operating System | Juniper | Junos | 22.4 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 22.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos | 22.4 | r2 | All | All |
| Operating System | Juniper | Junos | 22.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos | 22.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos | 22.4 | r3 | All | All |
| Operating System | Juniper | Junos | 22.4 | r3-s1 | All | All |
| Operating System | Juniper | Junos | 22.4 | r3-s2 | All | All |
| Operating System | Juniper | Junos | 22.4 | r3-s3 | All | All |
| Operating System | Juniper | Junos | 22.4 | r3-s4 | All | All |
| Operating System | Juniper | Junos | 23.2 | - | All | All |
| Operating System | Juniper | Junos | 23.2 | r1 | All | All |
| Operating System | Juniper | Junos | 23.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 23.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos | 23.2 | r2 | All | All |
| Operating System | Juniper | Junos | 23.2 | r2-s1 | All | All |
| Operating System | Juniper | Junos | 23.2 | r2-s2 | All | All |
| Operating System | Juniper | Junos | 23.4 | - | All | All |
| Operating System | Juniper | Junos | 23.4 | r1 | All | All |
| Operating System | Juniper | Junos | 23.4 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 23.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos | 23.4 | r2-s3 | All | All |
| Operating System | Juniper | Junos | 24.2 | - | All | All |
| Operating System | Juniper | Junos | 24.2 | r1 | All | All |
| Operating System | Juniper | Junos | 24.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos | 24.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | All | All | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r1-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r3-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r3-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r3-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 22.4 | r3-s4 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r1-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.2 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r1-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r1-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s2 | All | All |
| Operating System | Juniper | Junos Os Evolved | 23.4 | r2-s3 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | - | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r1 | All | All |
| Operating System | Juniper | Junos Os Evolved | 24.2 | r1-s2 | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Juniper Networks | Junos OS | affected 22.4R3-S5 semver | Not specified |
| CNA | Juniper Networks | Junos OS | affected 23.2 23.2R2-S3 semver | Not specified |
| CNA | Juniper Networks | Junos OS | affected 23.4 23.4R2-S4 semver | Not specified |
| CNA | Juniper Networks | Junos OS | affected 24.2 24.2R2 semver | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected all version prior to 22.4R3-S5-EVO semver | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 23.2 23.2R2-S3-EVO semver | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 23.4 23.4R2-S4-EVO semver | Not specified |
| CNA | Juniper Networks | Junos OS Evolved | affected 24.2 24.2R2-EVO semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| kb.juniper.net/JSA107819 | [email protected] | kb.juniper.net | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
Solutions
CNA: The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases; Junos OS: 22.4R3-S5, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases.
Workarounds
CNA: There are no known workarounds for this issue.
Exploits
CNA: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
There are currently no legacy QID mappings associated with this CVE.