How severe is CVE-2026-54982?

CVE-2026-54982 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-54982 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-54982?

CVE-2026-54982 primarily affects Microsoft Windows 10 1607. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-54982?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-54982 published?

CVE-2026-54982 was published on 2026-07-14 and last updated on 2026-07-20.

CVE-2026-54982

CVE-2026-54982 is a high-severity vulnerability in Microsoft Windows 10 1607 with a CVSS 3.x base score of 8.8. 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-191.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-191
Affected product: Microsoft Windows 10 1607
Published: 2026-07-14
Last modified: 2026-07-20

Description

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

Frequently asked questions

What is CVE-2026-54982?: Integer underflow (wrap or wraparound) in Reliable Multicast Transport Driver (RMCAST) allows an unauthorized attacker to execute code over an adjacent network.
How severe is CVE-2026-54982?: CVE-2026-54982 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over an adjacent network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-54982 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-54982?: CVE-2026-54982 primarily affects Microsoft Windows 10 1607. In total, 22 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-54982?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-54982 published?: CVE-2026-54982 was published on 2026-07-14 and last updated on 2026-07-20.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-54982

Affected products (22)

cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1607:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_1809:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_21h2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_10_22h2:*:*:*:*:*:*:x86:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_24h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_25h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26h1:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2012:-:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2012:r2:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2016:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:*:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:*:*

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Other CWE-191 (Integer Underflow) vulnerabilities

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CVE-2026-91103 — Critical (CVSS 9.8): HP has identified and remediated multiple externally reported vulnerabilities within HPLIP. The findings affect several…
CVE-2026-51540 — Critical (CVSS 9.8): OpENer 2.3.0 (master branch up to commit 76b95cf) is vulnerable to a severe memory corruption issue caused by an…
CVE-2026-53176 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: IB/isert: Reject login PDUs shorter than…
CVE-2026-37534 — Critical (CVSS 9.8): Integer underflow vulnerability in Open-SAE-J1939 thru commit b6caf884df46435e539b1ecbf92b6c29b345bdfe (2025-11-30) in…

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