CVE-2026-103993

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Out-of-Bounds Write in Juniper Junos OS BGP Communities Handling

Publication date: 2026-10-14

Last updated on: 2026-10-14

Assigner: Juniper Networks, Inc.

Description

An Out-of-bounds Write vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent attacker which sends a specific set of BGP communities to cause a Denial-of-Service (DoS) as rpd crashes when graceful-shutdown sender community is added when attempting to advertise.

CVSS Scores

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Meta Information

Published

2026-10-14

Last Modified

2026-10-14

Generated

2026-10-19

AI Q&A

2026-10-15

EPSS Evaluated

2026-10-18

NVD

CVE-2026-103993

EUVD

EUVD-2026-101453

Affected Vendors & Products

Vendor	Product	Version / Range
Juniper	Networks	Junos OS 0
Juniper	Networks	Junos OS 23.4
Juniper	Networks	Junos OS 24.2
Juniper	Networks	Junos OS 24.4
Juniper	Networks	Junos OS 25.2
Juniper	Networks	Junos OS 25.4
Juniper	Networks	Junos OS 26.2
Juniper	Networks	Junos OS Evolved 0
Juniper	Networks	Junos OS Evolved 23.4
Juniper	Networks	Junos OS Evolved 24.2
Juniper	Networks	Junos OS Evolved 24.4
Juniper	Networks	Junos OS Evolved 25.2
Juniper	Networks	Junos OS Evolved 25.4
Juniper	Networks	Junos OS Evolved 26.2
Juniper	Networks	Junos OS Evolved 23.4X100
Juniper	Networks	Junos OS Evolved 25.2X100
Juniper	Networks	Junos OS Evolved 25.4X300

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-787	The product writes data past the end, or before the beginning, of the intended buffer.

Attack-Flow Graph

Executive Summary

This is an Out-of-bounds Write vulnerability in Juniper Networks Junos OS and Junos OS Evolved. It occurs in the routing protocol daemon (rpd) and allows an adjacent attacker to send a specific set of BGP communities. When the graceful-shutdown sender community is added during route advertisement, it causes rpd to crash, leading to a Denial-of-Service (DoS).

Detection Guidance

This vulnerability involves a specific BGP community causing an out-of-bounds write in Junos OS or Junos OS Evolved. Detection requires monitoring for crashes in the routing protocol daemon (rpd) or unusual BGP community advertisements. Check logs for rpd crashes or unexpected DoS events. Juniper may provide specific commands in their advisories, but none are listed here.

Impact Analysis

This vulnerability can cause network disruption by crashing the routing protocol daemon (rpd), leading to service outages. If exploited, it may result in loss of network connectivity and routing instability, affecting communication and data transmission.

Compliance Impact

This vulnerability causes a Denial-of-Service (DoS) by crashing the routing protocol daemon (rpd) when specific BGP communities are sent. This could disrupt network availability, potentially leading to unauthorized data access or processing delays. Such disruptions may impact compliance with GDPR (data availability) and HIPAA (system reliability for healthcare data).

Mitigation Strategies

Apply the latest Junos OS or Junos OS Evolved patches from Juniper Networks to address the Out-of-bounds Write vulnerability in the routing protocol daemon (rpd). Disable BGP graceful-shutdown sender community if not required. Monitor rpd logs for crashes and restrict BGP community advertisements from untrusted sources.

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