cve-2025-53786

Security researcher Dirk‑jan Mollema’s discovery of two linked vulnerabilities in Microsoft’s Entra ID architecture exposed a failure mode that, by design, could have allowed an attacker with limited on‑premises access to gain near‑complete control over hybrid Microsoft environments — a chain...

Microsoft is taking the first concrete step in its phased enforcement of the dedicated Exchange hybrid app requirement: on September 16, 2025 at 07:00 UTC Microsoft will temporarily block Exchange Web Services (EWS) traffic that uses the Exchange Online shared service principal for hybrid...

Microsoft’s Exchange team published a short but important Hotfix Update (HU) rollup for September 2025 that is aimed at fixing a non‑security issue in earlier updates and, crucially, preserves support for the dedicated Exchange hybrid application workflow introduced earlier in 2025 — the update...

Microsoft has begun a strict, time‑boxed push to move Exchange hybrid customers off a Microsoft‑managed shared service principal and onto a dedicated Exchange hybrid app in Entra ID — a change driven by a high‑severity hybrid vulnerability and enforced through short, scheduled EWS traffic blocks...

Microsoft’s Exchange team has taken a decisive step toward finally letting organizations retire the last Exchange server in hybrid environments by adding cloud-managed remote mailbox support — a per-mailbox “flip-the-switch” that transfers Exchange attribute authority to Exchange Online while...

Microsoft's updated Exchange hybrid guidance — and a last‑minute change to the enforcement cadence — should be on every hybrid admin’s radar: the Exchange team has expanded the push to migrate hybrid traffic away from the long‑standing Exchange Online shared service principal into a tenant‑owned...

Microsoft’s Exchange team has given hybrid administrators a clear-but-urgent migration mandate: switch to the dedicated Exchange hybrid app and update on‑prem servers now, or face temporary disruptions in September and October followed by a permanent enforcement that will stop rich coexistence...

Microsoft’s August Patch Tuesday landed as a heavy, cross‑cutting security package that mixes high‑severity remote code execution (RCE) flaws, a publicly disclosed Kerberos elevation‑of‑privilege issue, and several cloud‑centric patches that were already mitigated on the service side—creating a...

A new wave of cybersecurity urgency is sweeping through IT departments as the Cybersecurity and Infrastructure Security Agency (CISA) issues a fresh, high-severity warning concerning Microsoft Exchange Server. The alert, centered around CVE-2025-53786, underscores a newly disclosed vulnerability...

A new high-severity security flaw in Microsoft Exchange Server hybrid deployments has placed organizations worldwide on high alert, raising the specter of a “total domain compromise” that can cascade from on-premises environments to Microsoft’s cloud. The bug, designated CVE-2025-53786, has not...

A sweeping emergency order from the U.S. Cybersecurity and Infrastructure Security Agency (CISA) has intensified the cybersecurity spotlight on Microsoft Exchange, following the disclosure of a fresh and serious vulnerability. On August 7th, 2025, CISA issued Emergency Directive 25-02 in direct...

A newly revealed security flaw in Microsoft Exchange hybrid configurations has sent ripples of concern through the IT community, as organizations with combined on-premises and cloud email environments are now exposed to invisible privilege escalation attacks. The critical vulnerability...

A newly disclosed security flaw in Microsoft Exchange hybrid deployments is triggering urgent action among IT administrators worldwide, as Microsoft warns of a critical vulnerability—CVE-2025-53786—that exposes hybrid environments to stealthy privilege escalation attacks. As organizations...

A new high-severity security vulnerability is causing alarm among businesses that utilize hybrid Microsoft Exchange deployments, as both Microsoft and the US Cybersecurity and Infrastructure Security Agency (CISA) issue urgent advisories. This flaw—affecting Exchange Server 2016, 2019, and the...

A critical security vulnerability, identified as CVE-2025-53786, has been discovered in hybrid deployments of Microsoft Exchange Server. This flaw allows attackers with local administrative access to escalate their privileges within connected cloud environments, posing significant risks to...

A high-severity security vulnerability has emerged at the heart of countless enterprise communications: Microsoft has issued a warning about a flaw in hybrid Exchange Server deployments that could give cyber attackers undetected escalated access to Exchange Online—potentially undermining the...

An alarming new vulnerability in Microsoft Exchange Server hybrid environments has sent shockwaves through the enterprise security landscape, giving attackers with just on-premises admin access the ability to hijack cloud accounts with near-complete impunity. Unveiled at Black Hat 2025 and now...

A high-severity vulnerability, designated CVE-2025-53786, has sent urgent ripples through the IT and cybersecurity communities as organizations relying on Microsoft’s hybrid Exchange deployments face a new vector for privilege escalation and potential domain-wide compromise. Microsoft has...

A critical security update has emerged for organizations leveraging Microsoft Exchange Server in hybrid cloud environments, as CVE-2025-53786 exposes a significant elevation of privilege vulnerability. On April 18th, 2025, Microsoft not only published important security changes for hybrid...