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Microsoft Patch Tuesday
April 2024

Microsoft's April 2024 Patch Tuesday fixes 150 vulnerabilities across Windows, SQL Server and Developer Tools - 3 rated Critical, 1 publicly disclosed before the patch shipped, one already exploited in the wild. Patch CVE-2024-26234 first.

Released April 9, 2024, 10:00 PT1 actively exploited1 publicly disclosed54 KB articles to deploy

April 2024 Patch Tuesday at a glance

150
Microsoft CVEs
excl. Edge & Azure Linux
3
Critical
2% of the release
1
Actively exploited
CVE-2024-26234
1
Publicly disclosed
known before the patch
9.0
Highest CVSS
CVE-2024-29990
54
KB articles
what you actually deploy

Why this number differs from other roundups. Microsoft's April 2024 release document lists 343 entries. 165 are Azure Linux (Mariner) OS package updates and 28 are republished Chromium fixes for Edge - neither is a Microsoft product vulnerability. The 150 above is the real Patch Tuesday set. See the breakdown →

Priority order

Patch these first

Ranked by exploitation reality, not score alone. This month's exploited flaw is rated Important - a severity-sorted list would bury it.

Patch this week

Publicly disclosed

Details are already public. Working exploits typically follow within days.

Nothing was disclosed before the patch shipped.

The numbers

What’s in this release

Where the 343 entries actually come from

Most roundups quote a single number. These are three unrelated release streams.

150 Microsoft products165 Azure Linux (Mariner)28 Edge (Chromium)

Severity

Microsoft channel only · 150 CVEs

April 2024 severity breakdown
Critical3
Important145
Moderate2
Low0

Impact type

What an attacker gains if it works

April 2024 impact breakdown
Remote Code Execution67
Elevation of Privilege31
Security Feature Bypass29
Information Disclosure13
Denial of Service7
Spoofing3

Most-affected components

Where this month’s fixes concentrate - filter by any of them in the table below

SQL Server38Windows Secure Boot26Windows Remote Access Connection Manager9Role: DNS Server7Microsoft Defender for IoT6Microsoft Brokering File System4Windows DHCP Server4Windows Kernel4Windows Routing and Remote Access Service (RRAS)3Microsoft WDAC OLE DB provider for SQL2Windows Authentication Methods2Windows Cryptographic Services2
Every patch

Browse all 343 entries

Sorted by risk by default: exploited first, then publicly disclosed, then severity, then CVSS. Search by CVE, title, component or KB number.

Showing 150 of 150
150 Microsoft vulnerabilities in the April 2024 Patch Tuesday, sortable by severity, CVSS and exploit status.
TitleStatusKB
ImportantCVE-2024-26234Proxy Driver Spoofing VulnerabilitySpoofing6.7ExploitedDisclosedWindows Proxy Driver5036892 +13
ImportantCVE-2024-29988SmartScreen Prompt Security Feature Bypass VulnerabilityBypass8.8More likelyInternet Shortcut Files5036892 +5
ImportantCVE-2024-26158Microsoft Install Service Elevation of Privilege VulnerabilityEoP7.8More likelyMicrosoft Install Service5036892 +13
ImportantCVE-2024-26211Windows Remote Access Connection Manager Elevation of Privilege VulnerabilityEoP7.8More likelyWindows Remote Access Connection Manager5036894 +8
ImportantCVE-2024-26218Windows Kernel Elevation of Privilege VulnerabilityEoP7.8More likelyWindows Kernel5036892 +5
ImportantCVE-2024-26230Windows Telephony Server Elevation of Privilege VulnerabilityEoP7.8More likelyWindows Remote Access Connection Manager5036892 +13
ImportantCVE-2024-26239Windows Telephony Server Elevation of Privilege VulnerabilityEoP7.8More likelyWindows Remote Access Connection Manager5036892 +8
ImportantCVE-2024-26241Win32k Elevation of Privilege VulnerabilityEoP7.8More likelyWindows Win32K - ICOMP5036892 +12
ImportantCVE-2024-26256Libarchive Remote Code Execution VulnerabilityRCE7.8More likelyWindows Compressed Folder5036893 +1
ImportantCVE-2024-26212DHCP Server Service Denial of Service VulnerabilityDoS7.5More likelyWindows DHCP Server5036896 +9
ImportantCVE-2024-28903Secure Boot Security Feature Bypass VulnerabilityBypass6.7More likelyWindows Secure Boot5036892 +9
ImportantCVE-2024-28921Secure Boot Security Feature Bypass VulnerabilityBypass6.7More likelyWindows Secure Boot5036892 +9
ImportantCVE-2024-26209Microsoft Local Security Authority Subsystem Service Information Disclosure VulnerabilityInfo Disc.5.5More likelyWindows Local Security Authority Subsystem Service (LSASS)5036892 +8
ImportantCVE-2024-29056Windows Authentication Elevation of Privilege VulnerabilityEoP4.3More likelyWindows Authentication Methods5036896 +9
CriticalCVE-2024-21323Microsoft Defender for IoT Remote Code Execution VulnerabilityRCE8.8—Microsoft Defender for IoT—
CriticalCVE-2024-29053Microsoft Defender for IoT Remote Code Execution VulnerabilityRCE8.8—Microsoft Defender for IoT—
CriticalCVE-2024-21322Microsoft Defender for IoT Remote Code Execution VulnerabilityRCE7.2—Microsoft Defender for IoT—
ImportantCVE-2024-29990Microsoft Azure Kubernetes Service Confidential Container Elevation of Privilege VulnerabilityEoP9.0—Microsoft Azure Kubernetes Service—
ImportantCVE-2024-20678Remote Procedure Call Runtime Remote Code Execution VulnerabilityRCE8.8—Windows Remote Procedure Call5036892 +13
ImportantCVE-2024-26179Windows Routing and Remote Access Service (RRAS) Remote Code Execution VulnerabilityRCE8.8—Windows Routing and Remote Access Service (RRAS)5036892 +13
ImportantCVE-2024-26200Windows Routing and Remote Access Service (RRAS) Remote Code Execution VulnerabilityRCE8.8—Windows Routing and Remote Access Service (RRAS)5036892 +13
ImportantCVE-2024-26205Windows Routing and Remote Access Service (RRAS) Remote Code Execution VulnerabilityRCE8.8—Windows Routing and Remote Access Service (RRAS)5036892 +13
ImportantCVE-2024-26210Microsoft WDAC OLE DB provider for SQL Server Remote Code Execution VulnerabilityRCE8.8—Microsoft WDAC OLE DB provider for SQL5036892 +13
ImportantCVE-2024-26214Microsoft WDAC SQL Server ODBC Driver Remote Code Execution VulnerabilityRCE8.8—Microsoft WDAC ODBC Driver5036892 +13
ImportantCVE-2024-26244Microsoft WDAC OLE DB provider for SQL Server Remote Code Execution VulnerabilityRCE8.8—Microsoft WDAC OLE DB provider for SQL5036892 +13
Your move

What your IT team should do

The same five steps every month, in the order that reduces risk fastest.

Test the known-issue candidates

Check the Windows release health dashboard before promoting past ring 1, and have the rollback path written down before you need it. Kernel, networking and authentication fixes are the ones that historically break things.

12 Patch Management Best Practices for 2026 →

Verify installed state, then evidence it

Confirm the patch is actually present on each endpoint rather than trusting that "deployment succeeded". Keep the resulting report - it is the artefact auditors ask for, and reconstructing it later is far more work than capturing it now.

Patch Management: The Complete Guide →

Trinetri does steps two through five automatically - detecting the 54 KB articles across every endpoint, staging them in rings, verifying installed state and producing the compliance evidence. See patch management →

Archive

Previous Patch Tuesdays

Every month Microsoft has published back to January 2016, each with the same breakdown and the full CVE list.

Older months104 releases, October 2024 – January 2016
Stop the sprawl. Eliminate the guesswork.

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Patch Tuesday FAQ

Patch Tuesday falls on the second Tuesday of every month, with updates going live at 10:00 a.m. Pacific Time. Microsoft introduced the practice in October 2003, following the Blaster worm, to cut distribution costs and give administrators a predictable cadence instead of patches arriving at random. The 10:00 a.m. timing is deliberate: it leaves a full working week to remediate before the weekend. Internally Microsoft calls it the "B" release; optional "C" and "D" preview releases follow later in the month. The next Patch Tuesday is November 10, 2026.

Microsoft fixed 150 vulnerabilities in April 2024, across Windows, SQL Server, Developer Tools and Azure. 3 are rated Critical, 1 were publicly disclosed before the patch shipped, and 1 was already being exploited. Note that Microsoft's release document lists 343 entries in total, but 165 of those are Azure Linux package updates and 28 are republished Chromium fixes for Edge, which is why other sources sometimes quote a much larger number.

Exploit Wednesday is the day after Patch Tuesday. Attackers compare the newly released patches against the previous version to locate the flaw each one fixes, then build working exploits from that difference - often within 24 to 48 hours. It is the reason the deployment window matters as much as the patch itself: every hour a Critical remote code execution fix sits undeployed is an hour of measurable exposure.

A workable target for most organisations: actively exploited vulnerabilities within 24 hours, publicly disclosed ones within 72 hours, remaining Critical fixes within seven days, and everything else within the month. CISA's Known Exploited Vulnerabilities catalogue sets binding deadlines for US federal agencies and is a reasonable benchmark for everyone else. Stage the rollout in rings rather than deploying everywhere at once, so a regression is caught on a pilot group instead of in production.

An out-of-band update is a patch released outside the monthly cycle because the risk will not wait for the next Patch Tuesday. Microsoft issues them for actively exploited flaws with no mitigation - most famously during the WannaCry outbreak in 2017, when it took the unusual step of patching versions of Windows that were already out of support.

Yes. Adobe aligned its releases with Patch Tuesday in November 2012, and both SAP's Security Patch Day and Oracle's quarterly Critical Patch Updates are coordinated to the same week. Part of the reason is defensive: staggered releases let attackers reverse-engineer one vendor's patch to find the same underlying flaw in another's still-unpatched product. For IT teams it means the second Tuesday is rarely just a Microsoft problem.

Edge is built on Chromium, so most of its security fixes originate with the Chromium project and are republished by Microsoft under their own CVE identifiers. They ship on Chromium's cadence rather than the Patch Tuesday cycle, and they are delivered by Edge's own updater rather than Windows Update. Counting the 28 Edge entries alongside Microsoft product fixes would inflate the headline number and imply work for your Windows Update rings that does not exist.