---
id: CVE-2026-28198
title: |-
  An authenticated, low-privileged user with access to the NetBackup Flex 
  OS management shell could bypass the cryptographic signature 
  verification step of a privileged support command by supplying a 
  specially formed access credential
summary: |-
  An authenticated, low-privileged user with access to the NetBackup Flex 
  OS management shell could bypass the cryptographic signature 
  verification step of a privileged support command by supplying a 
  specially formed access credential. …
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-347
vendor: Cohesity
product: NetBackup Flex OS
affected:
  - netbackup_flex_os < 6.4
published: '2026-09-18'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:24:36.593'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-28198'
references:
  - url: 'https://github.com/cohesity/SecAdvisory/blob/master/COH-2026-0001.md'
    label: a6d3dc9e-0591-4a13-bce7-0f5b31ff6158
  - url: 'https://www.cvcn.gov.it/cvcn/cve/CVE-2026-28198'
    label: a6d3dc9e-0591-4a13-bce7-0f5b31ff6158
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T14:14:16.330258Z'
ingestedAt: '2026-09-18T11:40:03.684Z'
epss: 0.0034
epssPercentile: 0.24628
---

## Overview

An authenticated, low-privileged user with access to the NetBackup Flex 
OS management shell could bypass the cryptographic signature 
verification step of a privileged support command by supplying a 
specially formed access credential. Successful exploitation grants the 
attacker an unrestricted root shell with full control over the Flex 
appliance host and all hosted containers, completely compromising 
confidentiality, integrity, and availability.

## Remediation

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