---
id: CVE-2026-68277
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/dp/mst: fix OOB reads on 2-byte fields in sideband reply parsers

  Three sideband reply parsers read 16-bit fields as:

    val = (raw->msg[idx] << 8) | (raw->msg[idx+…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/dp/mst: fix OOB reads on 2-byte fields in sideband reply parsers

  Three sideband reply parsers read 16-bit fields as:

    val = (raw->msg[idx] << 8) | (raw->msg[idx+…
severity: none
published: '2026-08-10'
updated: '2026-08-23'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68277'
references:
  - url: 'https://git.kernel.org/stable/c/0bcd7675c69a2462a8531fcd9e4d096e9c7ec5df'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/192e146c2d57ad033b0d418ec64ee390f8dc074e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/68a624416d1dd481b3e5b7ea0e8a070a9b8a2c73'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6b89ba3dba2f583626fb693e47e951ffb8bf591f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/6e3107e6522109a07fc9bb0fc4ec463f1982e113'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/bdf0508b1e6785d4a8982c637e97e68d60b47d7b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c1f72a13d54ffd16647d3fa540d961f5deba8790'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d5c70523cafa26ad2c7a37b612849abe2683baa8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.0022
epssPercentile: 0.11026
ingestedAt: '2026-08-23T13:48:06.862Z'
---

## Overview

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

drm/dp/mst: fix OOB reads on 2-byte fields in sideband reply parsers

Three sideband reply parsers read 16-bit fields as:

  val = (raw->msg[idx] << 8) | (raw->msg[idx+1]);

and check bounds only after the fact. When idx == raw->curlen,
raw->msg[idx+1] reads one byte past the received message data into
the following struct fields (curchunk_len, curchunk_idx, curlen).

Affected functions:
 - drm_dp_sideband_parse_enum_path_resources_ack()
   full_payload_bw_number and avail_payload_bw_number fields
 - drm_dp_sideband_parse_allocate_payload_ack()
   allocated_pbn field
 - drm_dp_sideband_parse_query_payload_ack()
   allocated_pbn field

Fix by using a single combined check (idx + 2 > curlen) before each
2-byte read. Since the check is strictly tighter than idx > curlen,
no separate step is needed.

[added fixes tag]

## Remediation

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