CVE-2026-28198 PUBLISHED

Privilege Escalation via Cryptographic Signature Verification Bypass in NetBackup Flex OS Shell

Assigner: ENISA
Reserved: 25.02.2026 Published: 18.09.2026 Updated: 18.09.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 9.4

Product Status

Vendor Cohesity
Product NetBackup Flex OS
Versions Default: unaffected
  • affected from 0 to 6.4 (excl.)

Workarounds

Restrict management shell access to authorized administrators only. No compensating control fully eliminates the risk; upgrading is required.

References

Problem Types

  • CWE-347 Improper verification of cryptographic signature CWE