# CVE-2026-64366: linux: In the Linux kernel, the following vulnerability has been resolved:  HID: wacom: fix slab-out-of-bounds write in waco...

CVE-2026-64366 is fixed in linux on 1 platform by DEBIAN-CVE-2026-64366 (version 7.1.4-1), released August 7, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-64366
- Priority: High
- CVSS: 8.8 (high)
- EPSS: 0.0040
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jul 25, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert  wacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo doesn't have enough space for the incoming report. If the kfifo is empty, kfifo_skip() reads stale data left in the kmalloc'd buffer via __kfifo_peek_n() and interprets it as a record length, advancing fifo->out by that garbage value. This corrupts the internal kfifo state, causing kfifo_unused() to return a value much larger than the actual buffer size, which bypasses __kfifo_in_r()'s guard:    if (len + recsize > kfifo_unused(fifo))       return 0;  kfifo_copy_in() then performs an out-of-bounds memcpy, writing up to 3842 bytes past the 256-byte buffer.  Add a !kfifo_is_empty() condition to the while loop so kfifo_skip() is never called on an empty fifo, and check the return value of kfifo_in() to reject reports that are too large for the fifo.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 7.1.4-1 | [DEBIAN-CVE-2026-64366](https://patchblox.com/security/data/fix/linux/debian-cve-2026-64366.md) | Aug 7, 2026 |

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Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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