CVE-2026-49788
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 · uneditedAllocation of resources without limits or throttling in HTTP/2 allows an unauthorized attacker to deny service 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 resource exhaustion vulnerability in HTTP/2 where the server fails to impose limits on resource allocation per connection or request. An attacker can exploit this by opening numerous simultaneous connections or streams, or by sending excessively large requests, causing the server to exhaust memory or CPU and deny service to legitimate users.
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< 10.0.28000.2269< 10.0.28000.2525< 10.0.14393.9339CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
-
Verify HTTP/2 is enabledCheck the Windows registry key HKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters for the EnableHttp2 value, or inspect IIS site bindings to confirm HTTP/2 protocol support is active.Affected if HTTP/2 is enabled and the Windows version falls within the affected ranges below.
-
Determine Windows versionRun 'winver' or execute 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to obtain the exact Windows build number.Affected if The build number is less than 10.0.14393.9339 (Windows 10 1607/Server 2016), 10.0.17763.9020 (Windows 10 1809), 10.0.19044.7548 (Windows 10 21h2), 10.0.19045.7548 (Windows 10 22h2), 10.0.26100.8875 (Windows 11 24h2), 10.0.26200.8875 (Windows 11 25h2), or 10.0.28000.2525/10.0.28000.2269 (Windows 11 2
-
Inspect HTTP/2 connection limitsCheck IIS configuration via appcmd list config or review the Windows registry under HKLM\SYSTEM\CurrentControlSet\Services\HTTP\Parameters for MaxConnections, MaxConcurrentRequests, or stream limit settings.Affected if No explicit connection, stream, or request size limits are configured on the HTTP/2 listener and the Windows version is within the affected ranges.
You are affected if HTTP/2 is enabled and your Windows build number is below the thresholds listed, and no connection or stream limits are configured on the server.
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
Implement and enforce HTTP/2 connection limits, maximum concurrent streams per connection, request size limits, and idle timeout configurations. Consider deploying a web application firewall or rate limiting at the edge to filter malicious traffic before it reaches the HTTP/2 service.
Windows 10 1607: build 10.0.14393.9339 | Windows 10 1809: build 10.0.17763.9020 | Windows 10 21h2: build 10.0.19044.7548 | Windows 10 22h2: build 10.0.19045.7548 | Windows 11 24h2: build 10.0.26100.8875 | Windows 11 25h2: build 10.0.26200.8875 | Windows 11 26h1: build 10.0.28000.2525 | Windows Serve
- Identify the current Windows version by running 'winver' or 'systeminfo' in Command Prompt
- Open Settings > Update & Security > Windows Update and check for updates, or manually download the applicable cumulative update from the Microsoft Update Catalog for your specific Windows version
- Apply the cumulative update that corresponds to your Windows version (e.g., KB5055522 for Windows 10 22h2, KB5055523 for Windows 11 24h2)
- Restart the computer when prompted to complete the installation
- Verify the update was successful by running 'winver' and confirming the build number matches or exceeds the fixed version for your Windows release
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-49788 — 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-2026-49788 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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.
- 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