Windows Search Component EUVD-2026-99571

Exploitation requires the attacker to already possess local, authenticated access to the target host (PR:L, AV:L) and the ability to run code that feeds crafted input to the Windows Search Component (the indexing/search service present by default on Windows). It cannot be triggered remotely or over a network, and no user interaction by a victim is needed (UI:N). The chief limiting factor is the prerequisite foothold: a standard local user account or existing code execution. Because Windows Search is enabled by default across supported Windows client and server editions, no special non-default configuration is needed beyond having the component present; patched builds (e.g. 10.0.26100.9711 for Windows 11 24H2, 10.0.19044.7807 for Windows 10 22H2, and the corresponding fixed builds per EUVD) are not exploitable.

This is a credible but not emergency-tier priority. The CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, base 7.8) describes a local privilege-escalation flaw: the attacker must already have local, authenticated (PR:L) code execution on the host before exploiting it, with low attack complexity and no user interaction required, yielding full confidentiality, integrity, and availability impact within an unchanged scope. No EPSS score, KEV listing, or POC indicator was supplied in the input, so there is no signal of active exploitation or public exploit code - status is 'no public exploit identified at time of analysis.' The signals are internally consistent: the description ('authorized attacker to elevate privileges locally') matches the PR:L/AV:L vector, so there is no conflict between the CVSS metrics and the narrative. The main risk driver is the ubiquity of Windows and the role of such local EoP bugs as the second-stage link in post-compromise and ransomware chains, rather than any confirmed in-the-wild use. Treat it as a routine-but-important patch-cycle item: high value to attackers who already have a foothold, low standalone risk because it cannot be triggered remotely or by an unauthenticated actor.

An attacker who has already gained low-privileged local code execution (for example via phishing, a malicious document, or a compromised standard user account) runs a crafted program that supplies malformed input to the Windows Search Component, triggering a heap-based buffer overflow (CWE-122). By controlling the corrupted heap memory, the attacker executes code in the context of the vulnerable service to escalate to SYSTEM. No public exploit code was identified in the provided data, and exploitation requires low attack complexity with no user interaction once local access exists.