How severe is CVE-2026-90891?

CVE-2026-90891 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-90891 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-90891?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2026-90891 published?

CVE-2026-90891 was published on 2026-09-14 and last updated on 2026-09-18.

CVE-2026-90891

CVE-2026-90891 is a medium-severity vulnerability with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-1256.

Key facts

Severity: Medium (CVSS 3.x base score 5.5)
CVSS v4: 6.8
EPSS exploit prediction: 0% (2nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-1256
Published: 2026-09-14
Last modified: 2026-09-18

Description

ASRock Polychrome SYNC/RGB software utility developed by ASRock Inc. has an Improper Access Control vulnerability. Authenticated local attackers can send a specially crafted IOCTL request to cause the driver to write to improperly restricted I/O ports, resulting in a forced operating system reboot.

Frequently asked questions

What is CVE-2026-90891?: ASRock Polychrome SYNC/RGB software utility developed by ASRock Inc. has an Improper Access Control vulnerability. Authenticated local attackers can send a specially crafted IOCTL request to cause the driver to write to improperly restricted I/O ports, resulting in a forced operating system reboot.
How severe is CVE-2026-90891?: CVE-2026-90891 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-90891 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-90891?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-90891 published?: CVE-2026-90891 was published on 2026-09-14 and last updated on 2026-09-18.

References

Other CWE-1256 vulnerabilities

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