Vulnerability · CVE-2026-20926
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network
Published Jan 13, 2026 · catalog updated Jul 30, 2026 · Microsoft Windows Server 2022
Last checked Oct 29, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-20926. EPSS is 0.80%. Act only if a listed version of Microsoft Windows Server 2022 is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
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- CVE-2025-54116 · High
- Severity
- High7.5
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.80%
- Remediation
- Version ranges on file
- Affected products
- vendor Microsoft Windows Server 2022 10.0.20348.0 <10.0.20348.4648
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Microsoft Windows Server 2022 10.0.20348.0 <10.0.20348.464810.0.20348.0 <10.0.20348.4648
How to fix CVE-2026-20926
Upgrade
CVE-2026-20926 lists a fix boundary at 10.0.20348.4648. Compare the installed build with that boundary before you change production.
Version check
Seen in 10.0.20348.0 <10.0.20348.4648
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-20926. EPSS is 0.80%. Act only if a listed version of Microsoft Windows Server 2022 is installed.
Which versions are affected?
Compare what you have installed with Microsoft Windows Server 2022 10.0.20348.0 <10.0.20348.4648 10.0.20348.0 <10.0.20348.4648. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.80%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jan 13, 2026 · EUVD
Detected
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
Jul 30, 2026 · EUVD
Updated
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
Sources
- CVE.orgVulnerability recordCVE-2026-20926
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-20926
30-day exploitation probability 0.80%
first.org - EUVDVulnerability recordEUVD-2026-2141
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows SMB Server allows an authorized attacker to elevate privileges over a network.
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Oct 29, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- CVE.orgOct 29, 2026
- FIRST EPSSOct 29, 2026
- EUVDOct 29, 2026