VULNERABILITY INTELLIGENCE

CVE-2026-21903

CVSS score6.5 MEDIUM
EPSS probability0.40%
CISA KEVNot currently listed
Published2026-01-15
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

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.

Weakness classification

  • sirt@juniper.net: CWE-121

Primary references