CVE-2026-93689 (GCVE-0-2026-93689)
Vulnerability from cvelistv5 – Published: 2026-09-18 15:06 – Updated: 2026-09-18 16:18
VLAI
EPSS
VEX
Title
WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/O
Summary
WinFsp through 2.2.26215 contains a null pointer dereference vulnerability in the kernel driver's Fast I/O device control handler that fails to validate the volume context before use. An unprivileged local user can trigger a denial of service by opening the WinFsp control device and issuing FSP_IOCTL_TRANSACT requests, causing a system crash.
Severity
5.5 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-18 16:18 UTC
CWE
- CWE-476 - NULL Pointer Dereference
Assigner
References
8 references
| URL | Tags |
|---|---|
| https://github.com/winfsp/winfsp/commit/b8103265e… | patch |
| https://github.com/winfsp/winfsp | product |
| https://github.com/winfsp/winfsp/blob/v2.2B4/src/… | technical-description |
| https://github.com/winfsp/winfsp/blob/v2.2B4/src/… | technical-description |
| https://github.com/winfsp/winfsp/blob/v2.2B4/src/… | technical-description |
| https://github.com/winfsp/winfsp/blob/v2.2B4/src/… | technical-description |
| https://github.com/winfsp/winfsp/releases/tag/v2.2B4 | release-notes |
| https://www.vulncheck.com/advisories/winfsp-throu… | third-party-advisory |
Impacted products
Date Public
2026-09-17 00:00
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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