Skip to main content
VulnerabilityPublished Updated

CVE-2026-64366: Linux kernel · HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High · fixed in ca899a926c11a59211b764b0155d9a1cdcc32b81 : patch Linux kernel soon.

Data as of 26 Oct 2026, 15:59 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in ca899a926c11a59211b764b0155d9a1cdcc32b81, 57bdd10ad50d68341f500a7b330f0d8949e510ec, 6b3014ec0e9a390ca563030b2d7689921f0daef5
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade Linux kernel to ca899a926c11a59211b764b0155d9a1cdcc32b81, 57bdd10ad50d68341f500a7b330f0d8949e510ec or 6b3014ec0e9a390ca563030b2d7689921f0daef5.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 5e013ad206895e72d7da41bc1ae89d8cb499c3aa, < ca899a926c11a59211b764b0155d9a1cdcc32b81
Fixed in
  • ca899a926c11a59211b764b0155d9a1cdcc32b81
LinuxLinuxAffected
  • ≥ 5e013ad206895e72d7da41bc1ae89d8cb499c3aa, < 57bdd10ad50d68341f500a7b330f0d8949e510ec
Fixed in
  • 57bdd10ad50d68341f500a7b330f0d8949e510ec
LinuxLinuxAffected
  • ≥ 5e013ad206895e72d7da41bc1ae89d8cb499c3aa, < 6b3014ec0e9a390ca563030b2d7689921f0daef5
Fixed in
  • 6b3014ec0e9a390ca563030b2d7689921f0daef5
LinuxLinuxAffected
  • =6.15
Fixed in–

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.

References

Community reviews

Loading reviews…