PatchTheCVECVE-2026-96909: Heap-based buffer overflow in Windows BitLocker allows an unauthorized attacker to execute code over a network
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CRITICAL 9.8REMOTEWATCHLISTUPGRADEUPGRADEUPGRADE
CVE-2026-96909 is a critical-severity flaw (CVSS 9.8) affecting windows 11 23h2, windows 11 24h2, windows 11 25h2. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Heap-based buffer overflow in Windows BitLocker allows an unauthorized attacker to execute code over a network.
Why this priority
- Critical severity
- CISA SSVC: automatable with total technical impact
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 9.8 (Critical) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.0% (top 38%) |
| CISA exploited list | No |
| Weakness | CWE-122 |
| Published | 2026-10-13 |
| Last modified | 2026-10-16 |
Publisher (CNA): Microsoft Corporation · Vendor: microsoft
Last updated 2026-10-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
microsoft windows 11 23h2 UPGRADE
Affected: < 10.0.22631.7652
Fixed in: 10.0.22631.7652
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
microsoft windows 11 24h2 UPGRADE
Affected: < 10.0.26100.9711
Fixed in: 10.0.26100.9711
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
microsoft windows 11 25h2 UPGRADE
Affected: < 10.0.26200.9711
Fixed in: 10.0.26200.9711
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
microsoft windows 11 26h1 UPGRADE
Affected: < 10.0.28000.3231
Fixed in: 10.0.28000.3231
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
microsoft windows 11 26h2 UPGRADE
Affected: < 10.0.26300.9711
Fixed in: 10.0.26300.9711
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
microsoft windows server 2022 UPGRADE
Affected: < 10.0.20348.5761
Fixed in: 10.0.20348.5761
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
Exact fixes by distribution
Install KB5126655 via Windows Update, then verify:
Get-HotFix -Id KB5126655
Windows Server 2022 (Server Core installation) · KB5126655 · FIXED · 10.0.20348.5761 · KB5126655 · source
Install KB5126655 via Windows Update, then verify:
Get-HotFix -Id KB5126655
Windows 11 Version 23H2 for ARM64-based Systems · KB5126653 · FIXED · 10.0.22631.7652 · KB5126653 · source
Install KB5126653 via Windows Update, then verify:
Get-HotFix -Id KB5126653
Windows 11 Version 23H2 for x64-based Systems · KB5126653 · FIXED · 10.0.22631.7652 · KB5126653 · source
Install KB5126653 via Windows Update, then verify:
Get-HotFix -Id KB5126653
Windows 11 Version 24H2 for ARM64-based Systems · KB5127648 · FIXED · 10.0.26100.9711 · KB5127648 · source
Install KB5127648 via Windows Update, then verify:
Get-HotFix -Id KB5127648
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-96909?
windows 11 23h2: upgrade to 10.0.22631.7652; windows 11 24h2: upgrade to 10.0.26100.9711; windows 11 25h2: upgrade to 10.0.26200.9711. Exact commands for each OS are on this page.
Is CVE-2026-96909 being exploited?
CVE-2026-96909 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-96909 affect?
CVE-2026-96909 affects windows 11 23h2, windows 11 24h2, windows 11 25h2. Severity is critical (CVSS 9.8). Heap-based buffer overflow in Windows BitLocker allows an unauthorized attacker to execute code over a network.
How urgent is CVE-2026-96909?
Priority 63/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist
Software pages
Windows vulnerabilities · Windows Server vulnerabilities · BitLocker vulnerabilities
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