CVE-2026-33797

Published Apr 9, 2026

Last updated 13 hours ago

CVSS high 7.1

Overview

Description
An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS). An attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS: * 25.2 versions before 25.2R2 This issue doesn't not affected Junos OS versions before 25.2R1. This issue affects Junos OS Evolved: * 25.2-EVO versions before 25.2R2-EVO This issue doesn't not affected Junos OS Evolved versions before 25.2R1-EVO. eBGP and iBGP are affected. IPv4 and IPv6 are affected.
Source
sirt@juniper.net
NVD status
Analyzed
Products
junos, junos_os_evolved

Risk scores

CVSS 4.0

Type
Secondary
Base score
7.1
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:C/RE:M/U:Green
Severity
HIGH

CVSS 3.1

Type
Primary
Base score
7.4
Impact score
4
Exploitability score
2.8
Vector string
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Severity
HIGH

Weaknesses

sirt@juniper.net
CWE-20

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. An Execution with Unnecessary Privileges vulnerability in the User Interface (UI) of Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privileged attacker to gain root privileges, thus compromising the system. When a configuration that allows unsigned Python op scripts is present on the device, a non-root user is able to execute malicious op scripts as a root-equivalent user, leading to privilege escalation.  This issue affects Junos OS:  * All versions before 22.4R3-S7,  * from 23.2 before 23.2R2-S4,  * from 23.4 before 23.4R2-S6, * from 24.2 before 24.2R1-S2, 24.2R2,  * from 24.4 before 24.4R1-S2, 24.4R2;  Junos OS Evolved:  * All versions before 22.4R3-S7-EVO,  * from 23.2 before 23.2R2-S4-EVO,  * from 23.4 before 23.4R2-S6-EVO, * from 24.2 before 24.2R2-EVO,  * from 24.4 before 24.4R1-S1-EVO, 24.4R2-EVO.•CVE-2026-33793
  2. An OS Command Injection vulnerability in the CLI processing of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker executing specific, crafted CLI commands to inject arbitrary shell commands as root, leading to a complete compromise of the system. Certain 'set system' commands, when executed with crafted arguments, are not properly sanitized, allowing for arbitrary shell injection. These shell commands are executed as root, potentially allowing for complete control of the vulnerable system. This issue affects: Junos OS:  * all versions before 22.4R3-S8,  * from 23.2 before 23.2R2-S5,  * from 23.4 before 23.4R2-S7,  * from 24.2 before 24.2R2-S2,  * from 24.4 before 24.4R2,  * from 25.2 before 25.2R2;  Junos OS Evolved:  * all versions before 22.4R3-S8-EVO,  * from 23.2 before 23.2R2-S5-EVO,  * from 23.4 before 23.4R2-S7-EVO,  * from 24.2 before 24.2R2-S2-EVO,  * from 24.4 before 24.4R2-EVO,  * from 25.2 before 25.2R1-S1-EVO, 25.2R2-EVO.•CVE-2026-33791
  3. A Missing Authorization vulnerability in the CLI of Juniper Networks Junos OS and Junos OS Evolved allows a local user with low privileges to read sensitive information. A local user with low privileges can execute the CLI command 'show mgd' with specific arguments which will expose sensitive information. This issue affects Junos OS: * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S6, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S4, * 24.4 versions before 24.4R2-S1, * 25.2 version before 25.2R1-S2, 25.2R2; Junos OS Evolved: * all versions before 23.2R2-S6-EVO, * 23.4 version before 23.4R2-S6-EVO, * 24.2 version before 24.2R2-S4-EVO, * 24.4 versions before 24.4R2-S1-EVO, * 25.2 versions before 25.2R2-EVO.•CVE-2026-33776
  4. An Incorrect Permission Assignment for Critical Resource vulnerability in the On-Box Anomaly detection framework of Juniper Networks Junos OS Evolved on PTX Series allows an unauthenticated, network-based attacker to execute code as root. The On-Box Anomaly detection framework should only be reachable by other internal processes over the internal routing instance, but not over an externally exposed port. With the ability to access and manipulate the service to execute code as root a remote attacker can take complete control of the device. Please note that this service is enabled by default as no specific configuration is required. This issue affects Junos OS Evolved on PTX Series: * 25.4 versions before 25.4R1-S1-EVO, 25.4R2-EVO. This issue does not affect Junos OS Evolved versions before 25.4R1-EVO. This issue does not affect Junos OS.•CVE-2026-21902
  5. A Use After Free vulnerability in the chassis daemon (chassisd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based attacker authenticated with low privileges to cause a Denial-of-Service (DoS). When telemetry collectors are frequently subscribing and unsubscribing to sensors continuously over a long period of time, telemetry-capable processes like chassisd, rpd or mib2d will crash and restart, which - depending on the process - can cause a complete outage until the system has recovered. This issue affects:  Junos OS:  * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2; Junos OS Evolved: * all versions before 22.4R3-S8-EVO, * 23.2 versions before 23.2R2-S5-EVO, * 23.4 versions before 23.4R2-EVO.•CVE-2026-21921

References

Sources include official advisories and independent security research.