Juniper Junos OS Vulnerability (JSA107850)

high Nessus Plugin ID 305584

Synopsis

The remote device is missing a vendor-supplied security patch.

Description

The version of Junos OS installed on the remote host is affected by a vulnerability as referenced in the JSA107850 advisory.

- 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 does not affect Junos OS versions before 25.2R1. This issue affects Junos OS Evolved: * 25.2-EVO versions before 25.2R2-EVO This issue does not affect Junos OS Evolved versions before 25.2R1-EVO. eBGP and iBGP are affected. IPv4 and IPv6 are affected. (CVE-2026-33797)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Apply the relevant Junos software release referenced in Juniper advisory JSA107850

See Also

http://www.nessus.org/u?0f42569b

Plugin Details

Severity: High

ID: 305584

File Name: juniper_jsa107850.nasl

Version: 1.5

Type: Combined

Published: 4/8/2026

Updated: 4/23/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v2

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 4.5

Vector: CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2026-33797

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.4

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: High

Base Score: 7.1

Threat Score: 4.9

Threat Vector: CVSS:4.0/E:U

Vector: 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

Vulnerability Information

CPE: cpe:/o:juniper:junos

Required KB Items: Host/Juniper/JUNOS/Version

Exploit Ease: No known exploits are available

Patch Publication Date: 4/8/2026

Vulnerability Publication Date: 4/8/2026

Reference Information

CVE: CVE-2026-33797

IAVA: 2026-A-0314

JSA: JSA107850