HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert
Published Jul 25, 2026
8.8
HIGHCVSS 3.1
EPSS 0.25%
Description
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.
Affected products
-
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
-
- Version 6.15StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<6.15
- Version 6.18.39StatusunaffectedConstraints<=6.18.*
- Version 7.1.4StatusunaffectedConstraints<=7.1.*
- Version 7.2StatusunaffectedConstraints<=*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
- ≥ 6.15 · < 6.18.39
- ≥ 6.19 · < 7.1.4
No data.
Red Hat Enterprise Linux 10
kernel
Affected
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel
Affected
Red Hat Enterprise Linux 9
kernel-rt
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
Jul–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.25% (0.00253) | 15.32th | v5 (v2026.06.15) |
| Jul 25, 2026 | 0.22% (0.00219) | 12.52th | v5 (v2026.06.15) |
References (8)
- https://access.redhat.com/security/cve/CVE-2026-64366 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2507252 Issue Tracking
- https://git.kernel.org/stable/c/57bdd10ad50d68341f500a7b330f0d8949e510ec Patch
- https://git.kernel.org/stable/c/6b3014ec0e9a390ca563030b2d7689921f0daef5 Patch
- https://git.kernel.org/stable/c/ca899a926c11a59211b764b0155d9a1cdcc32b81 Patch
- https://lore.kernel.org/linux-cve-announce/2026072522-CVE-2026-64366-52d4@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2026-64366
- https://www.cve.org/CVERecord?id=CVE-2026-64366
Change history (0)
No recorded changes yet.