CVE-2026-33799: 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 va

mediumCVSS 4.3CVE-2026-33799

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.

Details

Source: NVD Recent CVEs (US · database · site)
Severity: medium — CVSS 4.3
Published: 2026-07-09
Last updated: 2026-07-10
Exploitation: Not in CISA KEV at last sync

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

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-337990.36% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 28% of all scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-33799	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[NEW] [high] Juniper JUNOS and JUNOS Evolved: Multiple vulnerabilitiescert-bund
unknownJuniper Junos OS Multiple Vulnerabilitieshkcert
unknownMultiple vulnerabilities in Juniper Networks products (July 09, 2026)cert-fr-avis
unknownJuniper Networks security advisory (AV26-675)cccs

Recent advisories for An Out-of-bounds Write

A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.

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