CVE-2026-33780

April 9, 2026, 10:16 p.m.

7.1
High

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.

Product(s) Impacted

Vendor Product Versions
Juniper
  • Junos Os
  • Junos Os Evolved
  • <22.4R3-S5, 23.2, 23.4, 24.2
  • <22.4R3-S5-EVO, 23.2, 23.4, 24.2

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-401
Missing Release of Memory after Effective Lifetime
The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
o juniper junos_os <22.4R3-S5 / / / / / / /
o juniper junos_os 23.2 <23.2R2-S3 / / / / / /
o juniper junos_os 23.4 <23.4R2-S4 / / / / / /
o juniper junos_os 24.2 <24.2R2 / / / / / /
o juniper junos_os_evolved <22.4R3-S5-EVO / / / / / / /
o juniper junos_os_evolved 23.2 <23.2R2-S3-EVO / / / / / /
o juniper junos_os_evolved 23.4 <23.4R2-S4-EVO / / / / / /
o juniper junos_os_evolved 24.2 <24.2R2-EVO / / / / / /

References

https://kb.juniper.net/JSA107819

Tags

CWE-401
[email protected]
2026-04-09
CVE-2026-33780

CVSS Score

7.1 / 10

CVSS Data - 4.0

  • Attack Vector: ADJACENT
  • Attack Complexity: LOW
  • Attack Requirements: NONE
  • Privileges Required: NONE
  • User Interaction: NONE
  • Scope:
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: HIGH
  • Exploit Maturity: NOT_DEFINED

    • 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

    View Vector String

Timeline

Published: April 9, 2026, 10:16 p.m.
Last Modified: April 9, 2026, 10:16 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

[email protected]

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.