CVE & CISA-KEV Catalog

CVE-2026-54982

CRITICAL
8.8
CVSS v3
NVD

Description

Integer underflow (wrap or wraparound) in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over an adjacent network.

How to fix

Remediation Available
Windows 10 Version 1607Windows
Install:KB5099535Microsoft
Windows 10 Version 1809Windows
Install:KB5099538Microsoft
Windows 10 Version 21H2Windows
Install:KB5099539Microsoft
Windows 10 Version 22H2Windows
Install:KB5099539Microsoft
Windows 11 Version 24H2Windows
Install:KB5101650Microsoft
Windows 11 Version 25H2Windows
Install:KB5101650Microsoft
Windows 11 Version 26H1Windows
Install:KB5101649Microsoft
Windows 11 version 26H1Windows
Install:KB5101649Microsoft
Windows Server 2012Windows
Install:KB5099445Microsoft
Windows Server 2012 (Server Core installation)Windows
Install:KB5099445Microsoft
Windows Server 2012 R2Windows
Install:KB5099444Microsoft
Windows Server 2012 R2 (Server Core installation)Windows
Install:KB5099444Microsoft
Windows Server 2016Windows
Install:KB5099535Microsoft
Windows Server 2016 (Server Core installation)Windows
Install:KB5099535Microsoft
Windows Server 2019Windows
Install:KB5099538Microsoft
Windows Server 2019 (Server Core installation)Windows
Install:KB5099538Microsoft
Windows Server 2022Windows
Install:KB5099540Microsoft
Windows Server 2025Windows
Install:KB5099536Microsoft
Windows Server 2025 (Server Core installation)Windows
Install:KB5099536Microsoft

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorAdjacent
Attack ComplexityLow
Privileges RequiredNone
User InteractionNone
ScopeUnchanged

Impact

ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Exploit Intelligence

0.38%probability of exploitation in 30 days
31stpercentile

Low risk: more likely to be exploited than 31% of all known CVEs.

References

Related Vulnerabilities

Other CWE-191 vulnerabilities, ordered by exploit likelihood. View all

CVESeverityCVSSEPSSExploitedFix
CVE-2014-0497Critical9.8100%KEVFix
CVE-2020-36221High7.584%-Fix
CVE-2020-36228High7.583%-Fix
CVE-2023-31102High7.871%-Fix
CVE-2024-38063Critical9.871%-Fix
CVE-2017-14496High7.563%-Fix

Common questions

How do I fix CVE-2026-54982?

Published advisories record a fix for 19 affected products. The "How to fix" section on this page lists the fixed version and source advisory for each one, so apply the entry matching what you actually run.

Is CVE-2026-54982 being actively exploited?

Not that we know of. CVE-2026-54982 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.38% is the estimated probability that it will be exploited in the next 30 days. That is higher than 31% of all scored CVEs.

How severe is CVE-2026-54982?

CVE-2026-54982 has a CVSS v3 base score of 8.8, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-54982 affect?

Published advisories record a fix for Windows 10 Version 1607 (Windows), Windows 10 Version 1809 (Windows), Windows 10 Version 21H2 (Windows), Windows 10 Version 22H2 (Windows), and 15 more. Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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CVE-2026-54982 severity badge

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-20.