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Vulnerability record · CVE-2026-28198 · published 18 September 2026

CVE-2026-28198: Improper verification of cryptographic signature vulnerability

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.

9.4 CVSS 4.0 Critical EPSS 0.34% · top 75.2% CWE-347 · Improper verification of cryptographic signature Deferred
9.4CVSS 4.0 base score
0.34%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
2References
18 Sep 2026Last modified by NVD

Description

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.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://github.com/cohesity/SecAdvisory/blob/master/COH-2026-0001.md
https://www.cvcn.gov.it/cvcn/cve/CVE-2026-28198

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Source: NIST National Vulnerability Database (record CVE-2026-28198), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.