dbcve.org
Windows 10 1809Operating system · Microsoft

CVE-2026-20837

HIGH · 7.8 CVSS v3.1 Developing Published 2026-01-13
Fix available
A fix is available. Upgrade to 10.0.17763.8276 / 10.0.19044.6809 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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 · unedited
Heap-based buffer overflow in Windows Media allows an unauthorized attacker to execute code locally.

In the news

Third-party coverage
Trending covered by 1 outlet this week · latest 7mo ago

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 · low confidence
Developing — this CVE was published recently and its authoritative NVD entry is still being established, so we're holding a technical summary until the source data settles rather than publish something unreliable. Re-checking after 2026-08-12.

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
Windows 10 1809Operating system
Affected:< 10.0.17763.8276
Windows 10 21h2Operating system
Affected:< 10.0.19044.6809
Windows 10 22h2Operating system
Affected:< 10.0.19045.6809
Windows 11 23h2Operating system
Affected:< 10.0.22631.6491
Windows 11 24h2Operating system
Affected:< 10.0.26100.7623
Windows 11 25h2Operating system
Affected:< 10.0.26200.7623
Windows Server 2019Operating system
Affected:< 10.0.17763.8276
Windows Server 2022Operating system
Affected:< 10.0.20348.4648

CVSS 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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

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 · scoped
Upgrade available Upgrade to 10.0.17763.8276 / 10.0.19044.6809 / 10.0.19045.6809 or later
Fixed in 10.0.17763.827610.0.19044.680910.0.19045.6809
Recommended fix High confidence

Upgrade to the following minimum versions: Windows 10 1809 (10.0.17763.8276), Windows 10 21h2 (10.0.19044.6809), Windows 10 22h2 (10.0.19045.6809), Windows 11 23h2 (10.0.22631.6491), Windows 11 24h2 (10.0.26100.7623), Windows 11 25h2 (10.0.26200.7623), Windows Server 2019 (10.0.17763.8276), Windows

  1. Identify the current Windows version and build number by running 'winver' or 'systeminfo' in Command Prompt
  2. Determine which affected version category applies to your system (Windows 10 1809, 21h2, 22h2, Windows 11 23h2, 24h2, 25h2, Server 2019, or Server 2022)
  3. Open Windows Update by navigating to Settings > Update & Security > Windows Update
  4. Check for updates and install all available security updates
  5. Alternatively, manually download the specific security update from the Microsoft Update Catalog matching your Windows version and build (search for the KB article associated with this CVE)
  6. Restart the system after updates are installed
  7. Verify the installation was successful by checking that the build number matches or exceeds: Windows 10 1809: 10.0.17763.8276, Windows 10 21h2: 10.0.19044.6809, Windows 10 22h2: 10.0.19045.6809, Windows 11 23h2: 10.0.22631.6491, Windows 11 24h2: 10.0.26100.7623, Windows 11 25h2: 10.0.26200.7623, Windows Server 2019: 10.0.17763.8276, Windows Server 2022: 10.0.20348.4648
Caveat Standard Windows security update with minimal risk; as a local code execution fix, apply promptly after testing in non-production environments

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-20837 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • 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