CVE-2026-68278
Description
A flaw was found in the Linux kernel's DisplayPort (DP) Multi-Stream Transport (MST) subsystem. This vulnerability involves multiple buffer overflows within the drm_dp_sideband_append_payload() function when handling data from connected devices. A physically connected, malicious DP MST device can exploit this by sending specially crafted messages, leading to memory corruption. This could potentially allow an attacker to cause system instability or execute unauthorized code.
Mitigation
Prevent the 'drm_dp_mst' kernel module from loading to mitigate this vulnerability. This will disable DisplayPort Multi-Stream Transport functionality, which may affect multi-monitor setups using DisplayPort.
To blacklist the module, create a file named `/etc/modprobe.d/blacklist-drm_dp_mst.conf` with the following content:
blacklist drm_dp_mst
Then, regenerate the initramfs and reboot the system for the changes to take effect:
bash
drancut --force --kver $(uname -r)
reboot
A system reboot is required for the module to be unloaded and the mitigation to be active. This may impact display functionality if DP MST is in use.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.3 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | Low | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | High | N/A | N/A |
| Integrity Impact | Low | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of the product's implicit security policy. This can often be used to subvert any other security service.
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the product into an infinite loop.
Frequently Asked Questions
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