How severe is CVE-2026-96909?

CVE-2026-96909 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-96909 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-96909?

CVE-2026-96909 primarily affects Microsoft Windows 11 23h2. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-96909?

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

When was CVE-2026-96909 published?

CVE-2026-96909 was published on 2026-10-13 and last updated on 2026-10-16.

CVE-2026-96909

CVE-2026-96909 is a critical-severity vulnerability in Microsoft Windows 11 23h2 with a CVSS 3.x base score of 9.8. 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-122.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
EPSS exploit prediction: 1% (59th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-122
Affected product: Microsoft Windows 11 23h2
Published: 2026-10-13
Last modified: 2026-10-16

Description

Heap-based buffer overflow in Windows BitLocker allows an unauthorized attacker to execute code over a network.

Frequently asked questions

What is CVE-2026-96909?: Heap-based buffer overflow in Windows BitLocker allows an unauthorized attacker to execute code over a network.
How severe is CVE-2026-96909?: CVE-2026-96909 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-96909 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (59th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-96909?: CVE-2026-96909 primarily affects Microsoft Windows 11 23h2. In total, 12 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-96909?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-96909 published?: CVE-2026-96909 was published on 2026-10-13 and last updated on 2026-10-16.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-96909

Affected products (12)

cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_23h2:*:*:*:*:*:*:x64:*
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_11_26h2:*:*:*:*:*:*:arm64:*
cpe:2.3:o:microsoft:windows_11_26h2:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2022:*:*:*:*:*:*:x64:*
cpe:2.3:o:microsoft:windows_server_2025:*:*:*:*:*:*:x64:*

More vulnerabilities in Microsoft Windows 11 23h2

CVE-2025-49708 — Critical (CVSS 9.9): Use after free in Microsoft Graphics Component allows an authorized attacker to elevate privileges over a network.
CVE-2026-97816 — Critical (CVSS 9.8): Use after free in OpenSSH for Windows allows an unauthorized attacker to execute code over a network.
CVE-2026-97815 — Critical (CVSS 9.8): Heap-based buffer overflow in Windows Error Reporting allows an unauthorized attacker to execute code over a network.
CVE-2026-97814 — Critical (CVSS 9.8): Heap-based buffer overflow in Windows Text Shaping allows an unauthorized attacker to execute code over a network.
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CVE-2026-96924 — Critical (CVSS 9.8): Untrusted pointer dereference in Windows OLE allows an unauthorized attacker to execute code over a network.

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Other CWE-122 (Heap-based Buffer Overflow) vulnerabilities

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CVE-2026-24822 — Critical (CVSS 10.0): Out-of-bounds Write, Heap-based Buffer Overflow vulnerability in ttttupup wxhelper (src modules). This vulnerability is…
CVE-2025-23123 — Critical (CVSS 10.0): A malicious actor with access to the management network could execute a remote code execution (RCE) by exploiting a…
CVE-2022-34819 — Critical (CVSS 10.0): A vulnerability has been identified in SIMATIC CP 1242-7 V2 (All versions < V3.3.46), SIMATIC CP 1243-1 (All versions <…
CVE-2026-10858 — Critical (CVSS 9.9): IBM MQ for HPE NonStop 8.1.0 through 8.1.0.40 could allow an authenticated attacker to cause a denial of service or…

Browse all CWE-122 (Heap-based Buffer Overflow) vulnerabilities →