Out-of-bounds Write in Juniper Junos OS SNMPd before 23.4R2
CVE-2026-33799 Published on July 9, 2026
Junos OS and Junos OS Evolved: Receipt of a specific SNMPv3 request results in memory leak and eventual snmpd crash
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.
Vulnerability Analysis
CVE-2026-33799 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Weakness Type
What is a Memory Corruption Vulnerability?
The software writes data past the end, or before the beginning, of the intended buffer. Typically, this can result in corruption of data, a crash, or code execution. The software may modify an index or perform pointer arithmetic that references a memory location that is outside of the boundaries of the buffer. A subsequent write operation then produces undefined or unexpected results.
CVE-2026-33799 has been classified to as a Memory Corruption vulnerability or weakness.
Products Associated with CVE-2026-33799
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Affected Versions
Juniper Networks Junos OS:- Before 21.2R3-S8 is affected.
- Version 21.4 and below 21.4R3-S7 is affected.
- Version 22.1 and below 22.1R3-S6 is affected.
- Version 22.2 and below 22.2R3-S4 is affected.
- Version 22.3 and below 22.3R3-S3 is affected.
- Version 22.4 and below 22.4R3-S2 is affected.
- Version 23.2 and below 23.2R2 is affected.
- Version 23.4 and below 23.4R2 is affected.
- Before 21.2R3-S8-EVO is affected.
- Version 21.4 and below 21.4R3-S7-EVO is affected.
- Version 22.1 and below 22.1* is affected.
- Version 22.2 and below 22.2R3-S4-EVO is affected.
- Version 22.3 and below 22.3R3-S3-EVO is affected.
- Version 22.4 and below 22.4* is affected.
- Version 23.2 and below 23.2R2-EVO is affected.
- Version 23.4 and below 23.4R2-EVO is affected.