CyberSecBulletin
CVE-2026-64270NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-64270 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 040843281eebfa110d08fd7fb083fe6cb55cea14, 39b12daf1adb80f9595fdfe584961deb80860cbb, d99ba93c35ff2d5276e9c2632967481bd53a79d0 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 0.17% 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 040843281eebfa110d08fd7fb083fe6cb55cea14 or 39b12daf1adb80f9595fdfe584961deb80860cbb or d99ba93c35ff2d5276e9c2632967481bd53a79d0 or 5d2ea15ba03bf17ed143ff1a0995a4206edc3fb6, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.145 or 6.12.96 or 6.18.39 or 7.1.4, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, 040843281eebfa110d08fd7fb083fe6cb55cea14; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, 39b12daf1adb80f9595fdfe584961deb80860cbb; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, d99ba93c35ff2d5276e9c2632967481bd53a79d0; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, 5d2ea15ba03bf17ed143ff1a0995a4206edc3fb6; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, b78150729762d47c14fe29a2582bdca5568e62b8; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, 8301c335305344d4da4ab9442b6a399dacfe5b8d; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, f3d5e77b27fded71dcb97f409262bf0abba0410e; 07b8481d4aff73d6f451f25e74ea10240ff5131e up to, but not including, 66725039f7090afe14c31bd259e2059a68f04023; and 1 more ranges040843281eebfa110d08fd7fb083fe6cb55cea14, 39b12daf1adb80f9595fdfe584961deb80860cbb, d99ba93c35ff2d5276e9c2632967481bd53a79d0, 5d2ea15ba03bf17ed143ff1a0995a4206edc3fb6, b78150729762d47c14fe29a2582bdca5568e62b8, 8301c335305344d4da4ab9442b6a399dacfe5b8d
LinuxLinux Kernel3.6 up to, but not including, 6.6.145; 6.7 up to, but not including, 6.12.96; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.46.6.145, 6.12.96, 6.18.39, 7.1.4

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: Input: mms114 - reject an oversized device packet size mms114_interrupt() reads a packet of touch data from the device into a fixed-size on-stack buffer struct mms114_touch touch[MMS114_MAX_TOUCH]; which holds MMS114_MAX_TOUCH (10) events of MMS114_EVENT_SIZE (8) bytes, i.e. 80 bytes. The length of the I2C read into it is taken verbatim from the device: packet_size = mms114_read_reg(data, MMS114_PACKET_SIZE); if (packet_size <= 0) goto out; ... error = __mms114_read_reg(data, MMS114_INFORMATION, packet_size, (u8 *)touch); packet_size is a single device register byte (0x0F) and the only check is the lower bound packet_size <= 0; it is never bounded against the size of touch[]. A malfunctioning, malicious or counterfeit controller (or an attacker tampering with the I2C bus) can report a packet_size of up to 255, so __mms114_read_reg() writes up to 175 bytes past the end of touch[] on the IRQ-thread stack: a stack out-of-bounds write that can overwrite the stack canary, saved registers and the return address. A well-formed device never reports more than the buffer holds, so reject an oversized packet and drop the report, consistent with the handler's other error paths, rather than reading past the buffer.

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

References

Recent Out-of-bounds Write vulnerabilities

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