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CVE-2026-26176 Microsoft CVE debrief

The Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability is a high-severity vulnerability that allows an authorized attacker to elevate privileges locally. This vulnerability affects Windows 10, Windows 11, and Windows Server versions. Defenders should verify exposure, apply patches, and monitor for potential exploitation attempts. The CVE record was published on 2026-04-14T16:58:01.441Z and has not been modified since then. The NVD entry is currently HIGH. The vulnerability is caused by a heap-based buffer overflow in the Windows Client Side Caching driver (csc.sys).

Vendor
Microsoft
Product
Windows 10 Version 1607
CVSS
HIGH 7.8
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-14
Original CVE updated
2026-10-15
Advisory published
2026-04-14
Advisory updated
2026-10-15

Who should care

Defenders responsible for Windows systems, particularly those using Windows 10, Windows 11, and Windows Server versions, should assess exposure and apply patches.

Why it matters

CVE-2026-26176 is a high-severity elevation of privilege vulnerability in the Windows Client Side Caching driver (csc.sys). Defenders should verify exposure, apply patches, and monitor for potential exploitation attempts.

  • Verify exposure and apply patches to prevent potential privilege escalation
  • Monitor system logs for exploitation attempts
  • Implement compensating controls to limit damage
  • Assess and update vulnerability management processes

Technical summary

The Windows Client Side Caching driver (csc.sys) is vulnerable to a heap-based buffer overflow, allowing an authorized attacker to elevate privileges locally. This vulnerability affects Windows 10, Windows 11, and Windows Server versions. The vulnerability can be exploited by an attacker with local access to the system. The CVE Program record and NVD vulnerability detail provide information on the Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability.

Defensive priority

Defenders should prioritize verifying exposure and applying patches for Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability.

Recommended defensive actions

  • Verify exposure of Windows Client Side Caching driver (csc.sys) in the environment
  • Apply patches provided by Microsoft for the affected Windows versions
  • Monitor system logs for potential exploitation attempts
  • Implement compensating controls to limit potential damage

Evidence notes

The CVE Program record and NVD vulnerability detail provide information on the Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability. Microsoft's official advisory is referenced.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-26176 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-26176

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

  • CVE-2026-26176 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-26176

    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.