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CVE-2026-64084NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-64084 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 d0593e15fdeb56048a72c5c6e720f702759d0ccd, 17cee2f59029039416e8f6303050038eb59ba149, 299efd14c2eda7e5fd40025e54addd4151a01081 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 0.14% 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 d0593e15fdeb56048a72c5c6e720f702759d0ccd or 17cee2f59029039416e8f6303050038eb59ba149 or 299efd14c2eda7e5fd40025e54addd4151a01081 or 4d1da9a6be5a8156c532d571c2ed237169f99244, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.142, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxd98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, d0593e15fdeb56048a72c5c6e720f702759d0ccd; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, 17cee2f59029039416e8f6303050038eb59ba149; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, 299efd14c2eda7e5fd40025e54addd4151a01081; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, 4d1da9a6be5a8156c532d571c2ed237169f99244; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, b96c7f0bc0713dc6403912f6527d4ff9168d6fe6; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, fa7ca363069a70b0d1aa51e8892e3095fe2ac1ec; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, 2aef8f08c479f4cbc83e1e6b19d1c94d4dd24f17; d98dfad35c38c037b37c4adc99df01da571031a5 up to, but not including, d7834d92251baade796812876e95555e2066fa9f; and 1 more rangesd0593e15fdeb56048a72c5c6e720f702759d0ccd, 17cee2f59029039416e8f6303050038eb59ba149, 299efd14c2eda7e5fd40025e54addd4151a01081, 4d1da9a6be5a8156c532d571c2ed237169f99244, b96c7f0bc0713dc6403912f6527d4ff9168d6fe6, fa7ca363069a70b0d1aa51e8892e3095fe2ac1ec
LinuxLinux Kernel5.10 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.142; 6.7 up to, but not including, 6.12.92; 6.13 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 7.15.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34

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 CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/adm1266) cap PDIO scan in get_multiple at ADM1266_PDIO_NR adm1266_gpio_get_multiple() iterates the PDIO portion of the caller-supplied mask using for_each_set_bit_from(gpio_nr, mask, ADM1266_GPIO_NR + ADM1266_PDIO_STATUS) { ... } where ADM1266_PDIO_STATUS is the PMBus command code (0xE9, i.e. 233), not the number of PDIO pins. The intended upper bound is ADM1266_GPIO_NR + ADM1266_PDIO_NR = 25. gpiolib hands in a mask sized for gc.ngpio (= 25 bits on this chip), so the iteration walks find_next_bit() up to 242, reading up to 217 extra bits (a handful of unsigned-long words: four on 64-bit, seven on 32-bit) of whatever lives past the end of the mask in the caller's stack. Any incidental set bit in that range then drives a set_bit(gpio_nr, bits) call that writes past the end of the caller-supplied bits array too -- both out-of-bounds. Substitute ADM1266_PDIO_NR for the constant so the scan stops at the last real PDIO bit.

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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