CyberSecBulletin
CVE-2026-63967NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-63967 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions ff8d3c088b77b11782f2c3b97e37425be050e8de, fe1a7f99e72ebd2880515332b79b8c256be22aca, babf1943a40bb5669db57d30ca16c22504b18e07 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 0.16% 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 ff8d3c088b77b11782f2c3b97e37425be050e8de or fe1a7f99e72ebd2880515332b79b8c256be22aca or babf1943a40bb5669db57d30ca16c22504b18e07 or d42ac0bfb6a16617c62a59d53706579c7fadbfa6, 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
LinuxLinuxc14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, ff8d3c088b77b11782f2c3b97e37425be050e8de; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, fe1a7f99e72ebd2880515332b79b8c256be22aca; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, babf1943a40bb5669db57d30ca16c22504b18e07; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, d42ac0bfb6a16617c62a59d53706579c7fadbfa6; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, 3147b303b8c7d9f91da4b849ece33b45048f5eaf; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, e6bb3a49c5f9de870ea95e69775df785728e3366; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, 890d0312d5f94be43eac21f5a34d3bccc60d051b; c14edb4d0bdc53f969ea84c7f384472c28b1a9f8 up to, but not including, c9d8e9adaa63150ef7e833480b799d0bab83a276; and 3 more rangesff8d3c088b77b11782f2c3b97e37425be050e8de, fe1a7f99e72ebd2880515332b79b8c256be22aca, babf1943a40bb5669db57d30ca16c22504b18e07, d42ac0bfb6a16617c62a59d53706579c7fadbfa6, 3147b303b8c7d9f91da4b849ece33b45048f5eaf, e6bb3a49c5f9de870ea95e69775df785728e3366
LinuxLinux Kernel5.9.5 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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Official description

In the Linux kernel, the following vulnerability has been resolved: iio: imu: st_lsm6dsx: fix stack leak in tagged FIFO buffer The tagged FIFO path declares iio_buff on the stack with __aligned(8) but no initializer, but there is a hole in the structure, which will then leak to userspace as ST_LSM6DSX_SAMPLE_SIZE bytes (6) will be copied, but the space between that and the timestamp are not initialized. Commit c14edb4d0bdc ("iio:imu:st_lsm6dsx Fix alignment and data leak issues") moved the untagged FIFO path to a kzalloc'd buffer in hw->scan, but for the tagged path it only added the alignment qualifier and not the initializer :( Fix this by just zero-initializing the structure on the stack.

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. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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