December 10, 2025
5 Min Read

Microsoft addressed over 1,100 CVEs as part of Patch Tuesday releases in 2025, including 40 zero-day vulnerabilities.
Microsoft’s Patch Tuesday, a monthly release of software patches for Microsoft products, has just celebrated its 22nd anniversary. The Tenable Research Special Operations Team (RSO) first covered the 20th anniversary in 2023, followed by our 2024 year in review publication, covering the trends and significant vulnerabilities from the 2024 Patch Tuesday releases.
In 2025, Microsoft patched 1,130 CVEs throughout the year across a number of products. This was a 12% increase compared to 2024, when Microsoft patched 1,009 CVEs. With another year of Patch Tuesday releases behind us, Microsoft has yet to break its 2020 record with 1,245 CVE’s patched. However, this is the second year in a row that Microsoft crossed the 1,000 CVE threshold, and the third time since Patch Tuesday’s inception.

In 2025, Microsoft broke its record for the most CVEs patched in a month twice. The year started off with the largest Patch Tuesday release with 157 CVEs patched. This record was broken again in October with 167 CVEs patched.
Each month, Microsoft categorizes vulnerabilities into four main severity levels: low, moderate, important and critical.

Over the last three years, the bulk of the Patch Tuesday vulnerabilities continue to be rated as important. In 2025, 91.3% of all CVEs patched were rated important, followed by critical at 8.1%. Moderate accounted for 0.4%, while there were no CVEs rated as low in 2025.
In addition to severity levels, Microsoft also categorizes vulnerabilities by seven impact levels: remote code execution (RCE), elevation of privilege (EoP), denial of service (DoS), information disclosure, spoofing, security feature bypass and tampering.
In 2024, RCE vulnerabilities led the impact category, however 2025 saw EoP vulnerabilities taking the lead with 38.3% of all Patch Tuesday vulnerabilities. RCE accounted for 30.8%, followed by information disclosure flaws at 14.2% and DoS vulnerabilities at 7.7%. In a strange coincidence, this year there were only 4 CVEs categorized as tampering, which was the same in 2024. In both 2024 and 2025, tampering flaws accounted for only 0.4%.

In 2025, Microsoft patched 41 CVEs that were identified as zero-day vulnerabilities. Of the 41 CVEs, 24 were exploited in the wild. While not all zero-days were exploited, we classify zero-days as those vulnerabilities that were disclosed prior to being patched by the vendor.
Looking deeper at the 24 CVEs that were exploited in the wild, 62.5% were EoP flaws. EoP vulnerabilities are often leveraged by advanced persistent threat (APT) actors and determined cybercriminals seeking to elevate privileges as part of post-compromise activity. Following EoP flaws, RCEs were the second most prominent vulnerabilities across Patch Tuesday, accounting for 20.8% of zero-day flaws.

While only a small number of zero-days were addressed as part of 2025’s Patch Tuesday releases, we took a deeper dive into some of the more notable zero-days from the year. The table below includes these CVEs along with details on their exploitation activity.
| CVE | Description | Exploitation Activity |
|---|---|---|
| CVE-2025-24983 | Windows Win32 Kernel Subsystem Elevation of Privilege Vulnerability | Used with the PipeMagic backdoor to spread ransomware. |
| CVE-2025-29824 | Windows Common Log File System Driver Elevation of Privilege Vulnerability | Exploited by Storm-2460, also known as RansomEXX. Abused by the PipeMagic backdoor in order to spread ransomware. |
| CVE-2025-26633 | Microsoft Management Console Security Feature Bypass Vulnerability | Exploited by Water Gamayu (aka EncryptHub, Larva-208) to deploy the MSC EvilTwin trojan loader. The attack campaigns also saw several malware variants abused, including EncryptHub stealer, DarkWisp backdoor, SilentPrism backdoor, Stealc and the Rhadamanthys stealer. |
| CVE-2025-33053 | Internet Shortcut Files Remote Code Execution Vulnerability | Exploited by the APT known as Stealth Falcon (aka FruityArmor, G0038) to deploy Horus Agent malware. |
| CVE-2025-49704 | Microsoft SharePoint Remote Code Execution Vulnerability | Exploited by multiple APTs and nation-state actors including Linen Typhoon (aka Emissary Panda), Violet Typhoon, Storm-2603 and Warlock ransomware (aka GOLD SALEM). Chained with CVE-2025-49706 in an attack dubbed ToolShell. |
| CVE-2025-49706 | Microsoft SharePoint Server Spoofing Vulnerability | Exploited by multiple APTs and nation-state actors including Linen Typhoon (aka Emissary Panda), Violet Typhoon, Storm-2603 and Warlock ransomware (aka GOLD SALEM). Chained with CVE-2025-49704 in an attack dubbed ToolShell. |
With 2025’s Patch Tuesday releases in our rear-view mirror, it’s evident that we continue to see an upward trend in the number of vulnerabilities addressed year over year by Microsoft. With the lion's share of the market for operating systems, it’s imperative that defenders are quick to apply patches on the monthly release of Patch Tuesday updates. Attackers are often opportunistic and ready to capitalize on the latest exploitable vulnerabilities. As always, the RSO team will continue our monthly cadence of Patch Tuesday blogs, ensuring our readers have the actionable information necessary to take immediate action and improve their organization's security posture.
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