CyberSecBulletin
CVE-2026-63916NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-63916 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions 2add311d99646c9d235b2c44f9c169ba30f5db3a, 83bd8a5756a3c4a413ed8f6253f9eb2821e1ccaf, 5716a293fb19d382ca2336e08fd28a619a5f3c25 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 2add311d99646c9d235b2c44f9c169ba30f5db3a or 83bd8a5756a3c4a413ed8f6253f9eb2821e1ccaf or 5716a293fb19d382ca2336e08fd28a619a5f3c25 or ed598de9f61582902406d352d99f2073d8e00298, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, 2add311d99646c9d235b2c44f9c169ba30f5db3a; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, 83bd8a5756a3c4a413ed8f6253f9eb2821e1ccaf; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, 5716a293fb19d382ca2336e08fd28a619a5f3c25; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, ed598de9f61582902406d352d99f2073d8e00298; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, 43e7c02d6090a82fd60d63491f6871aec906345e; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, b8338111e14183972359009c12d0dbd81d2e1e16; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, 5db3fca0cec7b33bc5379411d0a60d792c9f9bc0; 5ae6e89f7409cb5d218bb728326eba9c650d9700 up to, but not including, c0a8899e02ddebd51e2589835182c239c2e224ae; and 1 more ranges2add311d99646c9d235b2c44f9c169ba30f5db3a, 83bd8a5756a3c4a413ed8f6253f9eb2821e1ccaf, 5716a293fb19d382ca2336e08fd28a619a5f3c25, ed598de9f61582902406d352d99f2073d8e00298, 43e7c02d6090a82fd60d63491f6871aec906345e, b8338111e14183972359009c12d0dbd81d2e1e16
LinuxLinux Kernel3.18 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.15.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: HID: wacom: Fix OOB write in wacom_hid_set_device_mode() wacom_hid_set_device_mode() currently assumes that the HID_DG_INPUTMODE usage is always located in the first field (field[0]) of the feature report. However, a device can specify HID_DG_INPUTMODE in a different field. If HID_DG_INPUTMODE is in a field other than the first one and the first field has a report_count smaller than the usage_index of HID_DG_INPUTMODE, this leads to an out-of-bounds write to r->field[0]->value. Fix this by storing the field index of HID_DG_INPUTMODE in 'struct hid_data' during feature mapping. In wacom_hid_set_device_mode(), use this stored field index to access the correct field and add bounds checks to ensure both the field index and the value index are within valid ranges before writing.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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