---
id: CVE-2026-101991
title: >-
  An Improper Handling of Length Parameter Inconsistency vulnerability in the
  routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS
  Evolved allows a configured BGP-LS peer to cause heap data disclosure via a
  malformed UPD…
summary: >-
  An Improper Handling of Length Parameter Inconsistency vulnerability in the
  routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS
  Evolved allows a configured BGP-LS peer to cause heap data disclosure via a
  malformed UPD…
severity: low
cvss: 3.1
cvssVector: 'CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'
cwe:
  - CWE-130
vendor: Juniper Networks
product: Junos OS
affected:
  - junos_os < 23.2R2-S7.7
  - junos_os >= 23.4 < 23.4R2-S8.13
  - junos_os >= 24.2 < 24.2R2-S5.5
  - junos_os >= 24.4 < 24.4R2-S5
  - junos_os >= 25.2 < 25.2R2-S2
  - junos_os >= 25.4 < 25.4R1-S3
  - junos_os >= 26.2 < 26.2R1-S2
  - junos_os_evolved < 23.2R2-S7.7-EVO
  - junos_os_evolved >= 23.4 < 23.4R2-S8.11-EVO
  - junos_os_evolved >= 24.2 < 24.2R2-S5.6-EVO
  - junos_os_evolved >= 24.4 < 24.4R2-S5-EVO
  - junos_os_evolved >= 25.2 < 25.2R2-S2-EVO
  - junos_os_evolved >= 25.4 < 25.4R1-S3-EVO
  - junos_os_evolved >= 26.2 < 26.2R1-S2-EVO
  - junos_os_evolved 23.4X100
  - junos_os_evolved >= 25.2X100 < 25.2X100-D35-EVO
  - junos_os_evolved >= 25.4X300 < 25.4X300-D40-EVO
published: '2026-10-14'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T16:23:06.250'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-101991'
references:
  - url: 'https://supportportal.juniper.net/JSA112187'
    label: sirt@juniper.net
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-14T20:37:46.018168Z'
ingestedAt: '2026-10-14T17:44:53.640Z'
epss: 0.00189
epssPercentile: 0.08477
---

## Overview

An Improper Handling of Length Parameter Inconsistency vulnerability in the routing protocol daemon (rpd) of Juniper Networks Junos OS and Junos OS Evolved allows a configured BGP-LS peer to cause heap data disclosure via a malformed UPDATE sent over a session with the traffic-engineering address family enabled.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.