---
id: CVE-2026-68279
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers

  drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw
  message and then unconditiona…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers

  drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw
  message and then unconditiona…
severity: none
published: '2026-08-10'
updated: '2026-08-23'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68279'
references:
  - url: 'https://git.kernel.org/stable/c/04d953f50d61e542e94a5977822cc53735f8c0ce'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/185de1d74e658e2edb723ba76fa61903f77d8a68'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/1a8f537f5a1eeac941f262fe73078d6b08ba83c0'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/22d9f7fc1aaabaf73d5f30e8b0c9aa814ecd6ed2'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/533d9e2bede4aeefdc2a0561d7071cfede95958f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c2fbda0fe0163c55ba3820ee6cea0c6b43622eda'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d7b9b1e33b4ed8c48d4db6e6e21c257ebbbb2586'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e6ef5455b06cb4e5d181aabcd723791587c79f12'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.0022
epssPercentile: 0.11109
ingestedAt: '2026-08-23T13:48:06.944Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

drm/dp/mst: fix OOB reads in remote DPCD/I2C sideband reply parsers

drm_dp_sideband_parse_remote_dpcd_read() reads num_bytes from the raw
message and then unconditionally does:

  memcpy(bytes, &raw->msg[idx], num_bytes);

without checking that idx + num_bytes <= raw->curlen. raw->msg[] is
256 bytes; if a malicious or misbehaving MST hub sets num_bytes larger
than the remaining payload, the memcpy reads past the received data
into whatever follows in raw->msg[].

drm_dp_sideband_parse_remote_i2c_read_ack() has the same flaw (noted
with a /* TODO check */ comment since the code was introduced).

Fix both functions by using a single combined check
(idx + num_bytes > curlen) before each memcpy. Since num_bytes is u8,
it is always >= 0, so this strictly subsumes the simpler idx > curlen
form and no separate step is needed.

[added missing fixes tag]

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.