HomeJuniperCVE-2026-21903

CVE-2026-21903

HIGH
7.1CVSS
Published: 2026-01-15
Updated: 2026-01-15
AI Analysis

Description

A Stack-based Buffer Overflow vulnerability in the Packet Forwarding Engine (pfe) of Juniper Networks Junos OS allows a network-based attacker, authenticated with low privileges to cause a Denial-of-Service (DoS). Subscribing to telemetry sensors at scale causes all FPC connections to drop, resulting in an FPC crash and restart. The issue was not seen when YANG packages for the specific sensors were installed. This issue affects Junos OS:  * all versions before 22.4R3-S7, * 23.2 version before 23.2R2-S4, * 23.4 versions before 23.4R2.

CVSS Metrics

Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/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:X/R:X/V:X/RE:X/U:X
Attack Vector
network
Complexity
low
Privileges
low
User Action
none
Confidentiality
undefined
Integrity
undefined
Availability
undefined
Weaknesses
CWE-121

Metadata

Primary Vendor
JUNIPER
Published
1/15/2026
Last Modified
1/15/2026
Source
NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

Juniper : Refer to Description

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CVE-CVE-2026-21903 | HIGH Severity | CVEDatabase.com | CVEDatabase.com