CVE-2026-43191

MEDIUM
Published May 6, 2026 Modified May 11, 2026

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.

CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0001
Probability of exploitation
0.03%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Affected Products

Vendor Product
linux linux_kernel

References

Frequently Asked Questions

What is CVE-2026-43191? +
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. It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2026-43191? +
CVE-2026-43191 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-43191? +
CVE-2026-43191 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-43191? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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