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CVE-2026-71340 Microsoft CVE debrief

CVE-2026-71340 is a high-severity vulnerability in the Windows File History Service, a component that allows users to create backups of files. The vulnerability is classified as a use-after-free issue, which can be exploited by an authorized attacker to elevate privileges locally. This type of vulnerability occurs when a program attempts to use memory after it has been freed, potentially leading to security risks. The CVE record was published on 2026-09-08T18:20:13.897Z and has not been modified since then. The NVD entry is currently Analyzed. The vulnerability requires local access to exploit and defenders should prioritize patching to prevent privilege escalation.

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-08
Original CVE updated
2026-09-15
Advisory published
2026-09-08
Advisory updated
2026-09-15

Who should care

Defenders responsible for Windows systems, especially those with high-risk exposure, should assess and prioritize patching this vulnerability.

Why it matters

CVE-2026-71340 is a high-severity vulnerability in Windows File History Service that requires local access to exploit. Defenders should prioritize patching to prevent privilege escalation.

  • Privilege escalation requires local access
  • Patching is required to prevent exploitation
  • Verify affected Windows versions and apply patches

Technical summary

The vulnerability is a use-after-free issue in the Windows File History Service, which allows an authorized attacker to elevate privileges locally. The CVSS score is 7, indicating high severity. This type of vulnerability can be particularly dangerous as it can be used to gain elevated privileges on a system, potentially leading to further exploitation. The vulnerability is not currently known to be exploited in the wild, but defenders should still prioritize patching. The affected product is Windows, and the vulnerability is

Defensive priority

Defenders should prioritize patching this vulnerability, especially for systems with high-risk exposure. Verify affected Windows versions and apply patches from Microsoft.

Recommended defensive actions

  • Patch affected Windows systems
  • Verify and apply Microsoft patches
  • Inventory and assess exposure of Windows File History Service

Evidence notes

The vulnerability is described as a use-after-free issue in the Windows File History Service. Microsoft has provided a patch for this vulnerability. The evidence is based on the CVE record and NVD entry, which provide official details about the vulnerability. However, the exact scope of affected systems and potential impact is not detailed in the CVE record or NVD entry. Defenders should verify affected Windows versions and apply patches from Microsoft. Additional verification may be

Sources and references

Verified primary and authoritative sources

  • CVE-2026-71340 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-71340

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-71340 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-71340

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.