CVE-2026-21903

HIGH EPSS 27.9%
Published Jan 15, 20265mo ago · Modified Jun 17, 20261w ago
7.1 CVSS 4.0
High
Find Similar
Published Jan 15, 2026 5mo ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
7.1
Exploitability
—
Impact
—
Vector string
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
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
27.9% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-121

Affected Products 27

VendorProductVersionRange
juniperjunos* <22.4
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos22.4any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.2any
juniperjunos23.4any
juniperjunos23.4any
juniperjunos23.4any
juniperjunos23.4any

References 2

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.