CVE-2026-33799 PUBLISHED

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

Assigner: juniper
Reserved: 23.03.2026 Published: 09.07.2026 Updated: 10.07.2026

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.

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CVSS Score: 4.3

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	None
User Interaction	None	Availability Impact	Low

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/AU:Y/R:A/V:C/RE:M/U:Green
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	None	Availability	Low	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	Juniper Networks
Product	Junos OS
Versions	Default: unaffected affected from 0 to 21.2R3-S8 (excl.) affected from 21.4 to 21.4R3-S7 (excl.) affected from 22.1 to 22.1R3-S6 (excl.) affected from 22.2 to 22.2R3-S4 (excl.) affected from 22.3 to 22.3R3-S3 (excl.) affected from 22.4 to 22.4R3-S2 (excl.) affected from 23.2 to 23.2R2 (excl.) affected from 23.4 to 23.4R2 (excl.)

Vendor	Juniper Networks
Product	Junos OS Evolved
Versions	Default: unaffected affected from 0 to 21.2R3-S8-EVO (excl.) affected from 21.4 to 21.4R3-S7-EVO (excl.) affected from 22.1 to 22.1* (excl.) affected from 22.2 to 22.2R3-S4-EVO (excl.) affected from 22.3 to 22.3R3-S3-EVO (excl.) affected from 22.4 to 22.4* (excl.) affected from 23.2 to 23.2R2-EVO (excl.) affected from 23.4 to 23.4R2-EVO (excl.)

Affected Configurations

This issue requires that SNMPv3 be configured. For example:

[snmp engine-id use-default-ip-address] [snmp v3 usm local-engine user <username> authentication-<method> ...] [snmp v3 vacm security-to-group security-model usm security-name <name> group <group>] [snmp v3 vacm access group <group> default-context-prefix security-model usm security-level <level> ...]

Exploits

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

Workarounds

There are no known workarounds for this issue.

To reduce the risk of malicious exploitation, use access lists or firewall filters to limit access to the device via SNMPv3 only from trusted hosts.

Solutions

The following software releases have been updated to resolve this specific issue:

Junos OS: 21.2R3-S8, 21.4R3-S7, 22.1R3-S6, 22.2R3-S4, 22.3R3-S3, 22.4R3-S2, 23.2R2, 23.4R2, 24.2R1, and all subsequent releases.

Junos OS Evolved: 21.2R3-S8-EVO, 21.4R3-S7-EVO, 22.2R3-S4-EVO, 22.3R3-S3-EVO, 23.2R2-EVO, 23.4R2-EVO, 24.2R1-EVO, and all subsequent releases.

References

https://supportportal.juniper.net/JSA110074

Problem Types

CWE-787 Out-of-bounds Write CWE