What is CVE-2026-33799?

CVE-2026-33799 is a medium-severity vulnerability in Juniper Junos, classified under Out-of-bounds Write. CVSS score: 4.3/10. Published 2026-07-09.

How severe is CVE-2026-33799?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Buffer overflow in Juniper Junos

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 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 class: Buffer Overflow

Published 2026-07-09 · last modified 2026-07-13.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.004 (28.5th percentile), scored 2026-10-09.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 28.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Juniper Junos — versions 21.2, 21.4, 22.1
Juniper Junos OS Evolved — versions 21.2, 21.4, 22.1
Juniper Networks Junos OS — versions 0, 21.4, 22.1
Juniper Networks Junos OS Evolved — versions 0, 21.4, 22.1

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

supportportal.juniper.net/JSA110074 (vendor-advisory, Mitigation, Vendor Advisory)

Frequently asked questions

What is CVE-2026-33799?: CVE-2026-33799 is a medium-severity vulnerability in Juniper Junos, classified under Out-of-bounds Write. CVSS score: 4.3/10. Published 2026-07-09.
How severe is CVE-2026-33799?: Medium severity. CVSS v3 base score is 4.3 out of 10.