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CVE-2026-33799 Juniper Networks CVE debrief

CVE-2026-33799 is an Out-of-bounds Write vulnerability in the SNMP daemon (snmpd) of Juniper Networks Junos OS and Junos OS Evolved. An authenticated network-based attacker can send specific valid SNMPv3 queries to trigger a memory leak, leading to snmpd process memory exhaustion, process crash, and restart. This impacts the ability to monitor the system via SNMP. Memory usage can be monitored using the command 'show system processes extensive | match snmpd'.

Vendor
Juniper Networks
Product
Junos OS
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-09
Original CVE updated
2026-07-13
Advisory published
2026-07-09
Advisory updated
2026-07-13

Who should care

Users of Juniper Networks Junos OS and Junos OS Evolved should be aware of this vulnerability and take steps to mitigate it. This includes administrators and security teams responsible for monitoring and maintaining network devices.

Technical summary

The vulnerability exists in the SNMP daemon (snmpd) of Juniper Networks Junos OS and Junos OS Evolved. An authenticated network-based attacker can exploit this by sending specific valid SNMPv3 queries, triggering a memory leak. Continuous receipt of these queries leads to snmpd process memory exhaustion, causing a process crash and restart. This affects the system's ability to be monitored via SNMP. The issue impacts multiple versions of Junos OS and Junos OS Evolved, specifically: 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.

Defensive priority

Medium priority due to the need for authentication and potential impact on system monitoring.

Recommended defensive actions

  • Apply patches or updates as provided by Juniper Networks for the affected versions of Junos OS and Junos OS Evolved.
  • Restrict SNMP access to trusted sources.
  • Monitor system processes for signs of memory exhaustion related to snmpd.
  • Implement compensating controls such as limiting SNMP queries.
  • Review system configurations for potential vulnerabilities.
  • Track and verify patch deployments for affected systems.
  • Conduct regular security audits to identify potential exposure.

Evidence notes

The CVE record was published on 2026-07-09T21:16:54.963Z and was last modified on 2026-07-10T14:16:52.830Z. The NVD entry is currently in the 'Received' status. Limited details are available about the exploitability and scope of the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-33799 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-33799

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-33799 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-33799

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.