CVE-2026-58546
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedUse of uninitialized resource in Windows RDP allows an unauthorized attacker to disclose information over a network.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Microsoft CVE Summary - Bleeping Computer
Surfaced from public web coverage — external links open in a new tab.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceThis is a use-of-uninitialized-resource vulnerability in Windows Remote Desktop Protocol (RDP). An unauthenticated attacker on the network can exploit this to disclose sensitive information due to the improper handling of memory resources during RDP operations.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 10.0.14393.9339< 10.0.17763.9020< 10.0.19044.7548< 10.0.19045.7548< 10.0.26100.8875< 10.0.26200.8875< 10.0.28000.2269all versions= r2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Verify RDP is enabled on the systemCheck the Windows registry key HKLM\SYSTEM\CurrentControlSet\Control\Terminal Server for the value "fDenyTSConnections" - a value of 0 means RDP is enabled. Alternatively, run `Get-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Control\Terminal Server' -Name fDenyTSConnections` in PowerShell.Affected if RDP is enabled (fDenyTSConnections = 0)
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Check the installed Windows 10 versionRun `winver` or `systeminfo | findstr /B /C:"OS Version"` to obtain the full version number. Compare against the affected ranges: 10.0.14393.9339 (1607), 10.0.17763.9020 (1809), 10.0.19044.7548 (21h2), 10.0.19045.7548 (22h2).Affected if Windows 10 version is lower than the specified threshold for your build (1607, 1809, 21h2, or 22h2)
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Check the installed Windows 11 versionRun `winver` or `systeminfo | findstr /B /C:"OS Version"` to obtain the full version number. Compare against the affected ranges: 10.0.26100.8875 (24h2), 10.0.26200.8875 (25h2), 10.0.28000.2269 (26h1).Affected if Windows 11 version is lower than the specified threshold for your build (24h2, 25h2, or 26h1)
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Check the installed Windows Server versionRun `systeminfo | findstr /B /C:"OS Name" /C:"OS Version"` to identify if the system is Windows Server 2012 or Windows Server 2012 R2. For Server 2012, all versions are affected per the advisory.Affected if The system is Windows Server 2012 or Windows Server 2012 R2 (all versions)
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Assess network exposure of RDPReview firewall rules and network configuration to determine if RDP port 3389 is open to untrusted or external networks. Check with `netsh advfirewall firewall show rule name=all | findstr /C:"3389"` and review inbound rules.Affected if RDP port 3389 is exposed to untrusted or external network segments
The system is affected if RDP is enabled AND the Windows version falls within any of the affected ranges listed AND the RDP service is network-accessible to untrusted hosts.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped10.0.14393.933910.0.17763.902010.0.19044.7548
Apply Microsoft security updates for Windows RDP as they become available. Ensure RDP is not exposed to untrusted networks and consider network-level authentication (NLA) as a compensating control.
Apply Microsoft security updates for this CVE to reach the fixed build numbers listed above
- Check current Windows version by running 'winver' or 'systeminfo' to confirm the installed build number
- Apply the latest Windows security updates via Windows Update, or download specific patches from Microsoft Update Catalog
- For Windows Server 2012/2012 R2 (all versions), apply the applicable security update from Microsoft KB list for this CVE
- After patching, verify the installed version matches or exceeds the fixed build: 10.0.14393.9339 (Win10 1607), 10.0.17763.9020 (Win10 1809), 10.0.19044.7548 (Win10 21h2), 10.0.19045.7548 (Win10 22h2), 10.0.26100.8875 (Win11 24h2), 10.0.26200.8875 (Win11 25h2), or 10.0.28000.2269 (Win11 26h1)
- If RDP is not required, consider disabling it to reduce attack surface
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-58546 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-58546 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data