Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-23988 is a high-severity Time-of-check Time-of-use (TOCTOU) Race Condition (CWE-367) vulnerability in Akeo Rufus. Its CVSS base score is 7.3 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Path Interception (T1034); ranked at the 10th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to AC-25 (Reference Monitor) and AC-3 (Access Enforcement) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-23988 is a time-of-check to time-of-use (TOCTOU) race condition vulnerability, classified under CWE-367, affecting Rufus versions 4.11 and earlier. Rufus is a utility for formatting and creating bootable USB flash drives. The issue resides in the src/net.c component during the creation, validation, and execution of the Fido PowerShell script. With a CVSS v3.1 base score of 7.3 (AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H), the vulnerability arises because Rufus runs with elevated Administrator privileges but writes the script to the %TEMP% directory, which is writable by standard users, without properly locking the file.
A local attacker with low privileges can exploit this by replacing the legitimate PowerShell script with a malicious one in the %TEMP% directory between the write and execution steps, as Rufus does not prevent concurrent access. This requires the victim to run Rufus as Administrator, introducing a user interaction element. Successful exploitation enables arbitrary code execution with Administrator privileges, potentially leading to full system compromise.
The vulnerability has been addressed in Rufus version 4.12_BETA, as detailed in the project's GitHub security advisory (GHSA-hcx5-hrhj-xhq9), release notes, and the fixing commit (460cc5768aa45be07941b9e4ebc9bee02d282873). Security practitioners should advise users to update to 4.12_BETA or later and avoid running Rufus from untrusted environments.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-4202
Vulnerability Data
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…
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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.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V15.4.2V17.2.6
Mitigating Controls (NIST 800-53 r5) AI
A reference monitor that is always invoked and analyzable structurally eliminates the non-atomic check-then-use pattern underlying TOCTOU.
Access enforcement that performs an atomic check-and-use decision directly stops the window in which a TOCTOU race can be exploited.
Process isolation limits the blast radius of a successful TOCTOU exploitation but does not remove the race itself.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly include coding standards and reviews that prevent TOCTOU race conditions.