CVE-2026-33799: Junos OS and Junos OS Evolved: Receipt of a specific SNMPv3 request results in memory leak and eventual snmpd crash

Published Jul 9, 2026
·
Updated

An Out-of-bounds Write vulnerability in the SNMP daemon (snmpd) of Juniper Networks Junos OS and Junos OS Evolved allows an authenticated network-based attacker sending specific valid SNMPv3 queries to trigger a memory leak. Over time, continuous receipt of these queries will result in snmpd process memory exhaustion, resulting in a process crash and restart, impacting the ability to monitor the system via SNMP.

Memory usage can be monitored using the following command:

user@device> show system processes extensive | match snmpd

This issue affects:

Junos OS:

all versions before 21.2R3-S8; from 21.4 before 21.4R3-S7; from 22.1 before 22.1R3-S6; from 22.2 before 22.2R3-S4; from 22.3 before 22.3R3-S3; from 22.4 before 22.4R3-S2; from 23.2 before 23.2R2; from 23.4 before 23.4R2.

Junos OS Evolved: all versions before 21.2R3-S8-EVO; from 21.4 before 21.4R3-S7-EVO; all versions of 22.1-EVO, from 22.2 before 22.2R3-S4-EVO; from 22.3 before 22.3R3-S3-EVO; all versions of 22.4-EVO, from 23.2 before 23.2R2-EVO; from 23.4 before 23.4R2-EVO.

Affected Software

142 affected components
Juniper Networks Junos OS<21.2R3-S8, >21.4<21.4R3-S7, >22.1<22.1R3-S6, >22.2<22.2R3-S4, >22.3<22.3R3-S3, >22.4<22.4R3-S2, >23.2<23.2R2, >23.4<23.4R2
Juniper Networks Junos OS Evolved<21.2R3-S8-EVO, >21.4<21.4R3-S7-EVO, >22.1-EVO<22.1-EVO, >22.2<22.2R3-S4-EVO, >22.3<22.3R3-S3-EVO, >22.4-EVO<22.4-EVO, >23.2<23.2R2-EVO, >23.4<23.4R2-EVO
Juniper Junos<21.2
Juniper Junos=21.2
Juniper Junos=21.2-r1
Juniper Junos=21.2-r1-s1
Juniper Junos=21.2-r1-s2
Juniper Junos=21.2-r2
Juniper Junos=21.2-r2-s1
Juniper Junos=21.2-r2-s2
Juniper Junos=21.2-r3
Juniper Junos=21.2-r3-s1
Juniper Junos=21.2-r3-s2
Juniper Junos=21.2-r3-s3
Juniper Junos=21.2-r3-s4
Juniper Junos=21.2-r3-s5
Juniper Junos=21.2-r3-s6
Juniper Junos=21.2-r3-s7
Juniper Junos=21.4
Juniper Junos=21.4-r1
Juniper Junos=21.4-r1-s1
Juniper Junos=21.4-r1-s2
Juniper Junos=21.4-r2
Juniper Junos=21.4-r2-s1
Juniper Junos=21.4-r2-s2
Juniper Junos=21.4-r3
Juniper Junos=21.4-r3-s1
Juniper Junos=21.4-r3-s2
Juniper Junos=21.4-r3-s3
Juniper Junos=21.4-r3-s4
Juniper Junos=21.4-r3-s5
Juniper Junos=21.4-r3-s6
Juniper Junos=22.1
Juniper Junos=22.1-r1
Juniper Junos=22.1-r1-s1
Juniper Junos=22.1-r1-s2
Juniper Junos=22.1-r2
Juniper Junos=22.1-r2-s1
Juniper Junos=22.1-r2-s2
Juniper Junos=22.1-r3
Juniper Junos=22.1-r3-s1
Juniper Junos=22.1-r3-s2
Juniper Junos=22.1-r3-s3
Juniper Junos=22.1-r3-s4
Juniper Junos=22.1-r3-s5
Juniper Junos=22.2
Juniper Junos=22.2-r1
Juniper Junos=22.2-r1-s1
Juniper Junos=22.2-r1-s2
Juniper Junos=22.2-r2
Juniper Junos=22.2-r2-s1
Juniper Junos=22.2-r2-s2
Juniper Junos=22.2-r3
Juniper Junos=22.2-r3-s1
Juniper Junos=22.2-r3-s2
Juniper Junos=22.2-r3-s3
Juniper Junos=22.3
Juniper Junos=22.3-r1
Juniper Junos=22.3-r1-s1
Juniper Junos=22.3-r1-s2
Juniper Junos=22.3-r2
Juniper Junos=22.3-r2-s2
Juniper Junos=22.3-r3
Juniper Junos=22.3-r3-s1
Juniper Junos=22.3-r3-s2
Juniper Junos=22.4
Juniper Junos=22.4-r1
Juniper Junos=22.4-r1-s1
Juniper Junos=22.4-r1-s2
Juniper Junos=22.4-r2
Juniper Junos=22.4-r2-s1
Juniper Junos=22.4-r2-s2
Juniper Junos=22.4-r3
Juniper Junos=22.4-r3-s1
Juniper Junos=23.2
Juniper Junos=23.2-r1
Juniper Junos=23.2-r1-s1
Juniper Junos=23.2-r1-s2
Juniper Junos=23.4
Juniper Junos=23.4-r1
Juniper Junos=23.4-r1-s1
Juniper Junos=23.4-r1-s2
Juniper Junos OS Evolved<21.2
Juniper Junos OS Evolved=21.2
Juniper Junos OS Evolved=21.2-r1
Juniper Junos OS Evolved=21.2-r1-s1
Juniper Junos OS Evolved=21.2-r1-s2
Juniper Junos OS Evolved=21.2-r2
Juniper Junos OS Evolved=21.2-r2-s1
Juniper Junos OS Evolved=21.2-r2-s2
Juniper Junos OS Evolved=21.2-r3
Juniper Junos OS Evolved=21.2-r3-s1
Juniper Junos OS Evolved=21.2-r3-s2
Juniper Junos OS Evolved=21.2-r3-s3
Juniper Junos OS Evolved=21.2-r3-s4
Juniper Junos OS Evolved=21.2-r3-s5
Juniper Junos OS Evolved=21.2-r3-s6
Juniper Junos OS Evolved=21.2-r3-s7
Juniper Junos OS Evolved=21.4
Juniper Junos OS Evolved=21.4-r1
Juniper Junos OS Evolved=21.4-r1-s1
Juniper Junos OS Evolved=21.4-r1-s2
Juniper Junos OS Evolved=21.4-r2
Juniper Junos OS Evolved=21.4-r2-s1
Juniper Junos OS Evolved=21.4-r2-s2
Juniper Junos OS Evolved=21.4-r3
Juniper Junos OS Evolved=21.4-r3-s1
Juniper Junos OS Evolved=21.4-r3-s2
Juniper Junos OS Evolved=21.4-r3-s3
Juniper Junos OS Evolved=21.4-r3-s4
Juniper Junos OS Evolved=21.4-r3-s5
Juniper Junos OS Evolved=21.4-r3-s6
Juniper Junos OS Evolved=22.1
Juniper Junos OS Evolved=22.2
Juniper Junos OS Evolved=22.2-r1
Juniper Junos OS Evolved=22.2-r1-s1
Juniper Junos OS Evolved=22.2-r1-s2
Juniper Junos OS Evolved=22.2-r2
Juniper Junos OS Evolved=22.2-r2-s1
Juniper Junos OS Evolved=22.2-r2-s2
Juniper Junos OS Evolved=22.2-r3
Juniper Junos OS Evolved=22.2-r3-s1
Juniper Junos OS Evolved=22.2-r3-s2
Juniper Junos OS Evolved=22.2-r3-s3
Juniper Junos OS Evolved=22.3
Juniper Junos OS Evolved=22.3-r1
Juniper Junos OS Evolved=22.3-r1-s1
Juniper Junos OS Evolved=22.3-r1-s2
Juniper Junos OS Evolved=22.3-r2
Juniper Junos OS Evolved=22.3-r2-s2
Juniper Junos OS Evolved=22.3-r3
Juniper Junos OS Evolved=22.3-r3-s1
Juniper Junos OS Evolved=22.3-r3-s2
Juniper Junos OS Evolved=22.4
Juniper Junos OS Evolved=23.2
Juniper Junos OS Evolved=23.2-r1
Juniper Junos OS Evolved=23.2-r1-s1
Juniper Junos OS Evolved=23.2-r1-s2
Juniper Junos OS Evolved=23.4
Juniper Junos OS Evolved=23.4-r1
Juniper Junos OS Evolved=23.4-r1-s1
Juniper Junos OS Evolved=23.4-r1-s2

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 21.2R3-S8-EVO
  2. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 21.4R3-S7-EVO
  3. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 22.2R3-S4-EVO
  4. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 22.3R3-S3-EVO
  5. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 23.2R2-EVO
  6. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 23.4R2-EVO
  7. Upgrade

    Upgrade Juniper Networks Junos OS Evolved to a version that resolves this vulnerability.

    Fixed in 24.2R1-EVO
  8. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 21.2R3-S8
  9. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 21.4R3-S7
  10. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 22.1R3-S6
  11. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 22.2R3-S4
  12. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 22.3R3-S3
  13. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 22.4R3-S2
  14. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 23.2R2
  15. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 23.4R2
  16. Upgrade

    Upgrade Juniper Networks Junos OS to a version that resolves this vulnerability.

    Fixed in 24.2R1
  17. Configuration

    Mitigate exploitation by blocking or restricting the network sources or SNMPv3 queries that match the description of the specific valid SNMPv3 requests that cause the memory leak and eventual snmpd crash.

    snmpd (SNMP daemon) Authenticated SNMPv3 query handling = Block/limit receipt of the specific valid SNMPv3 queries that trigger the out-of-bounds write
  18. Compensating control

    Monitor snmpd memory usage while applying mitigations using: user@device> show system processes extensive | match snmpd

Event History

Jul 9, 2026
CVE Published
via MITRE·09:02 PM
Data Sourced
via MITRE·09:02 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·09:16 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-33799?

CVE-2026-33799 has a medium severity rating of 4.3.

2

How do I fix CVE-2026-33799?

To mitigate CVE-2026-33799, apply the recommended patches or updates provided by Juniper Networks for Junos OS and Junos OS Evolved.

3

What causes CVE-2026-33799?

CVE-2026-33799 is caused by an out-of-bounds write vulnerability in the SNMP daemon (snmpd) within Juniper Networks' Junos operating systems.

4

What are the potential consequences of CVE-2026-33799?

The potential consequences of CVE-2026-33799 include a memory leak and eventual crashing of the snmpd process due to continuous SNMPv3 queries from an authenticated attacker.

5

Who is affected by CVE-2026-33799?

CVE-2026-33799 affects users of Juniper Networks' Junos OS and Junos OS Evolved who utilize the SNMP daemon.

Company

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