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CVE-2026-28198: CWE-347 Improper verification of cryptographic signature in Cohesity NetBackup Flex OS

0
Critical
VulnerabilityCVE-2026-28198cvecve-2026-28198cwe-347
Published: 09/18/2026 (09/18/2026, 11:12:23 UTC)
Source: CVE Database V5
Vendor/Project: Cohesity
Product: NetBackup Flex OS

Description

CVE-2026-28198 is a critical vulnerability in Cohesity NetBackup Flex OS that allows an authenticated, low-privileged user with access to the management shell to bypass cryptographic signature verification of a privileged support command. Exploiting this flaw grants the attacker unrestricted root shell access, compromising the entire appliance host and all hosted containers. This results in full control over confidentiality, integrity, and availability of the system.

CVSS v4.0

Score 9.4critical

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
None
Privileges Required
Low
User Interaction
None
Vuln. Confidentiality
High
Vuln. Integrity
High
Vuln. Availability
High
Subsq. Confidentiality
High
Subsq. Integrity
High
Subsq. Availability
High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Affected software

Cohesity

NetBackup Flex OS

Affected versions
>=0 <6.4
GitHub Actionsmore threats →ai
cohesity/NetBackup-Flex-OS
pkg:github/cohesity/NetBackup-Flex-OS
Affected versions
>=0 <6.4

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AI-Powered Analysis

Machine-generated threat intelligence

AILast updated: 09/18/2026, 22:15:48 UTC

Technical Analysis

This vulnerability involves improper verification of cryptographic signatures (CWE-347) in NetBackup Flex OS. An attacker with low privileges and access to the management shell can supply a specially crafted access credential to bypass signature verification on a privileged support command. Successful exploitation leads to an unrestricted root shell, allowing complete control over the Flex appliance host and all containers it hosts.

Potential Impact

Successful exploitation grants an attacker full root access to the Flex appliance host and all hosted containers, resulting in total compromise of confidentiality, integrity, and availability of the system.

Mitigation Recommendations

No patch or remediation information is provided. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance.

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Technical Details

Data Version
5.2
Assigner Short Name
ENISA
Date Reserved
2026-02-25T14:02:29.493Z
Cvss Version
4.0
State
PUBLISHED

Threat ID: 6aadb77255bf5e2cf59e6421

Added to database: 09/18/2026, 22:13:06 UTC

Last enriched: 09/18/2026, 22:15:48 UTC

Last updated: 09/19/2026, 02:14:08 UTC

Views: 6

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