ZeroHour

Search: “esu”

80 stories

Patch Tuesday - September 2026

Microsoft's September 2026 Patch Tuesday fixes 999 CVEs, a record, with two zero-day privilege escalation flaws already exploited in the wild.

Microsoft published 974 own-product vulnerabilities plus 25 non-Microsoft CVEs, totaling 999 — the most CVEs Microsoft has ever released in a single day. Two flaws are exploited in the wild: CVE-2026-85880, an out-of-bounds write in Windows ALPC granting SYSTEM privileges, and CVE-2026-81963, an improper link resolution flaw in the Windows Update Stack also leading to SYSTEM. Chrome's V8 zero-day CVE-2026-85046 was patched in Edge on September 2, but Microsoft had not published a corresponding advisory, leaving uncertainty about other Chromium fixes in Edge. October 14 lifecycle changes end servicing for Windows 11 24H2 Home/Pro, Office 2021, and Exchange Server 2016/2019.

Rapid7 Blog · 7d agoVulnerability in the wildCVE-2026-85880CVE-2026-81963CVE-2026-85046+10 CVEs

Microsoft releases Windows 10 KB5122878 extended security update

Microsoft shipped Windows 10 ESU update KB5122878, delivering the record September 2026 Patch Tuesday fixes, including patches for two actively exploited zero-days.

Microsoft released KB5122878 for Windows 10 Enterprise LTSC and ESU customers, moving builds 19045/19044 to .7725 with security and bug fixes. The update carries this month's record September 2026 Patch Tuesday set, which fixed 966 Microsoft vulnerabilities including two actively exploited zero-day flaws. It also fixes BitLocker recovery-key prompts and Remote Desktop audio redirection, and updates Secure Boot certificate rollout and Morocco time zone data. Microsoft reports no known issues with the update.

BleepingComputer · 7d agoAdvisory in the wild

September 2026 Patch Tuesday forecast: All we need is more time

September 2026 Patch Tuesday forecast expects record CVE volume after August's 398 fixes, with SharePoint flaws CVE-2026-55040 and CVE-2026-63520 actively exploited.

This Patch Tuesday forecast column notes August 2026 Patch Tuesday was the second largest ever with 398 resolved CVEs, yet only one was confirmed actively exploited. SharePoint flaws CVE-2026-55040 and CVE-2026-63520 are being chained for authentication bypass and remote code execution in active attacks against unpatched servers. Microsoft Defender's ShieldBreak elevation of privilege flaw (CVE-2026-69414) is publicly disclosed with PoC code and a fix is expected, while Chrome CVE-2026-85046 was reported exploited in the wild. Several products, including Windows 11 24H2 Home/Pro and Exchange Server 2016/2019 ESU, reach end of support in October 2026.

Help Net Security · 7d agoAdvisory in the wildCVE-2026-55040CVE-2026-63520CVE-2026-62911+5 CVEs1

Microsoft Exchange Vulnerability CVE-2026-62911: What Administrators Should Do and How Zscaler Can Help

High-severity authentication bypass CVE-2026-62911 in Exchange Server has public exploit code; about 22,000 servers remain unpatched and internet-exposed.

Microsoft's August 2026 Patch Tuesday fixed CVE-2026-62911 (CVSS 8.0), an authentication bypass affecting Exchange Server 2016, 2019 and Subscription Edition. Successful exploitation lets an attacker with basic privileges take over all mailboxes on the targeted server, including reading and sending email and downloading attachments. As of September 1, Shadowserver identified roughly 22,000 unpatched, internet-exposed Exchange servers, including about 6,200 in the US and 5,100 in Germany. NCSC-NL confirmed working exploit code is publicly available, while CISA has not yet reported exploitation in the wild.

Zscaler ThreatLabz · 12d agoVulnerabilityCVE-2026-629112

Nearly 22,000 Microsoft Exchange servers remain exposed to critical security flaw (CVE-2026-62911)

About 22,000 Microsoft Exchange servers remain unpatched against critical auth bypass CVE-2026-62911 as a working exploit circulates online.

CVE-2026-62911 is a critical authentication bypass by capture-replay in Microsoft Exchange Server that allows an authorized attacker to elevate privileges over the network, with a CVSS score of 8.0. Microsoft patched the flaw on August 11, 2026, but Shadowserver Foundation scans show roughly 22,000 servers unpatched, with the US (6,200) and Germany (5,100) leading; BSI reports 85% of on-premises Exchange servers in Germany are still vulnerable. The Netherlands' NCSC-NL flagged that a working exploit is circulating, and Exchange 2016/2019 require the Extended Security Updates program for fixes.

Help Net Security · 14d agoExploit / PoC in the wildCVE-2026-62911CVE-2026-42897

August 2026 Patch Tuesday forecast: How do we deal with the patch apocalypse?

August 2026 Patch Tuesday forecast urges risk-based triage as AI inflates CVE volume, flags actively exploited SharePoint RCE CVE-2026-50522 and LegacyHive Windows flaw.

July 2026 Patch Tuesday set records with over 600 CVEs, including 405 for Windows 11 and Server 2025, though only two were exploited zero-days and one was publicly disclosed. The author recommends prioritizing known-exploited and internet-facing vulnerabilities, matching patches to high-risk systems, and accelerating ring-based deployment toward Microsoft's suggested three-day turnaround. Notable items include actively exploited SharePoint RCE CVE-2026-50522 enabling machine key theft, the unassigned LegacyHive Windows User Profile Service flaw, and several end-of-servicing dates for Windows and Exchange.

Help Net Security · 22d agoIndustry in the wildCVE-2026-505221

Windows Server 2022 reaches end of mainstream support next month

Microsoft says Windows Server 2022 ends mainstream support on October 13, 2026, entering extended security updates through October 14, 2031.

Windows Server 2022, the September 2021 Long-Term Servicing Channel release, will receive its last mainstream support update with the October 2026 security patch. After October 13, 2026, it transitions to extended support with free monthly security updates through October 14, 2031. Microsoft also extended hotpatching for Datacenter: Azure Edition until October 2027 and recommends upgrading to Windows Server 2025, the current LTSC release.

BleepingComputer · 8h agoIndustry