CyberSecBulletin
CVE-2026-23178NVD status: Deferred

Linux: Heap-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2026-23178 is a high-severity heap-based buffer overflow 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 f9c9ad89d845f88a1509e9d672f65d234425fde9, cff3f619fd1cb40cdd89971df9001f075613d219, 786ec171788bdf9dda38789163f1b1fbb47f2d1e 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 0.19% 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 f9c9ad89d845f88a1509e9d672f65d234425fde9 or cff3f619fd1cb40cdd89971df9001f075613d219 or 786ec171788bdf9dda38789163f1b1fbb47f2d1e or 2124279f1f8c32c1646ce98e75a1a39b23b7db76, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux85df713377ddc0482071c3e6b64c37bd1e48f1f1 up to, but not including, f9c9ad89d845f88a1509e9d672f65d234425fde9; 85df713377ddc0482071c3e6b64c37bd1e48f1f1 up to, but not including, cff3f619fd1cb40cdd89971df9001f075613d219; 85df713377ddc0482071c3e6b64c37bd1e48f1f1 up to, but not including, 786ec171788bdf9dda38789163f1b1fbb47f2d1e; 85df713377ddc0482071c3e6b64c37bd1e48f1f1 up to, but not including, 2124279f1f8c32c1646ce98e75a1a39b23b7db76; 85df713377ddc0482071c3e6b64c37bd1e48f1f1 up to, but not including, 2497ff38c530b1af0df5130ca9f5ab22c5e92f29; 5.18f9c9ad89d845f88a1509e9d672f65d234425fde9, cff3f619fd1cb40cdd89971df9001f075613d219, 786ec171788bdf9dda38789163f1b1fbb47f2d1e, 2124279f1f8c32c1646ce98e75a1a39b23b7db76, 2497ff38c530b1af0df5130ca9f5ab22c5e92f29

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: HID: i2c-hid: fix potential buffer overflow in i2c_hid_get_report() `i2c_hid_xfer` is used to read `recv_len + sizeof(__le16)` bytes of data into `ihid->rawbuf`. The former can come from the userspace in the hidraw driver and is only bounded by HID_MAX_BUFFER_SIZE(16384) by default (unless we also set `max_buffer_size` field of `struct hid_ll_driver` which we do not). The latter has size determined at runtime by the maximum size of different report types you could receive on any particular device and can be a much smaller value. Fix this by truncating `recv_len` to `ihid->bufsize - sizeof(__le16)`. The impact is low since access to hidraw devices requires root.

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

The underlying weakness: Heap-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the heap.

How developers prevent this class of flaw

  • Pre-design: Use a language or compiler that performs automatic bounds checking.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • 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 Heap-based Buffer Overflow vulnerabilities (CWE-122)

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 Heap-based Buffer Overflow vulnerabilities

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