Remember last month when we were awed by Microsoft’s record-setting Patch Tuesday that addressed 206 CVEs? That was a quaint era compared to this month: Redmond just rolled out patches for 622 CVEs specific to its products, slightly more than tripling last month’s all-time high.Redmond’s Patch Tuesday release is once again one for the record books, with everything under the sun getting some security fixes – including 428 non-Microsoft Chromium CVEs affecting Edge that aren’t included in that 622 count. Fifty-eight of those are critical, two are under active exploit, and one has already been publicly disclosed, meaning it could join those other two in short order.There is a lot to dig through, and we can hardly cover the whole gamut given the size of this release. As we noted last month, there was concern in the infosec community that AI-enabled bug hunting might mean massive patch volumes are the new normal. Microsoft didn’t disclose how much AI may have contributed to the massive patch list this month, but given the volume it’s safe to say human contributors probably had some assistance.
Microsoft’s massive month
To start, let’s cover the pair of actively exploited issues that Microsoft patched. The first, CVE-2026-56155, is an Active Directory Federation Services elevation of privilege vulnerability. Attackers who exploit the issue, which Microsoft only described as being due to “insufficient granularity of access control on ADFS,” could gain administrator privileges. They do need to have access already and be local, however, which is why this is only rated with a CVSS score of 7.8. The second actively exploited vulnerability, CVE-2026-56164, is another privilege elevation issue, this time in Microsoft SharePoint. SharePoint is apparently missing authentication for a critical function, which could let an unauthorized attacker on a network elevate their SharePoint permissions. As with the other issue under exploit, this one is somewhat limited, earning it a CVSS of just 5.3. With both under active exploitation, that score doesn’t matter as much as eliminating the vulnerability through good patch management, however. As for the publicly reported but not-yet-exploited issue, CVE-2026-50661, that involves BitLocker being able to have its security measures physically bypassed by anyone with local access to a BitLocker-secured machine. Now let’s round up a few of those 58 critical issues.Everyone’s favorite untrustworthy AI is packing a CVSS 9.6 remote code execution vulnerability. CVE-2026-48561 finds Copilot improperly neutralizing its input, allowing an unauthorized attacker to execute code with nothing but low-privileged Hyper-V guest access. Exploiting the vulnerability can be done without user awareness by, for example, hosting a malicious website that prompts the many embedded Copilot features of Windows machines to process a prompt upon landing on the page. Microsoft Exchange is suffering from a CVSS 9.6 spoofing vuln due to failure to neutralize input, leading to cross-site scripting being possible from within a maliciously crafted email. CVE-2026-55008 allows an unauthorized attacker to perform spoofing over a network by sending said malicious email to a target, allowing arbitrary JavaScript execution.
