CVE-2026-93689

MEDIUMPre-NVD 5.55.5—
EchelonGraph scoreHIGH confidence

Score 5.5 from GitHub Security Advisory published 2026-09-18. The CNA's CVSS baseline 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cna:vulncheck, epss, ghsa
Trending — 3 sources updated this week
5.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 5.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
5.5
EG Score
5.5MEDIUMhigh confidence
EG Risk
25
EG Risk 25/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity55% × 45%
Exploitation0% × 40%
Automatability0% × 15%
CISA SSVC: Track at every mission impact level.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
3rd
KEV
Not listed

CISA SSVCTrack at every mission impact level.

A fix is available. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 18, 2026

Last Modified

September 24, 2026

Advisory Details (8)

Auto-updated Sep 18, 2026
Patch available. Sources: github_commit, github_release.
generic

WinFsp through 2.2.26215 NULL Pointer Dereference via Fast I/O | Advisories | VulnCheck

https://www.vulncheck.com/advisories/winfsp-through-2.2.26215-null-pointer-dereference-via-fast-i-o
github_release Patch Available

WinFsp 2026 Beta4

Patch available: winfsp/winfsp v2.2B4 (pre-release)

https://github.com/winfsp/winfsp/releases/tag/v2.2B4
generic

winfsp/src/sys/volume.c at v2.2B4 · winfsp/winfsp · GitHub

https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/volume.c#L1059-L1060
generic

winfsp/src/sys/devctl.c at v2.2B4 · winfsp/winfsp · GitHub

https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L146-L152
generic

winfsp/src/sys/devctl.c at v2.2B4 · winfsp/winfsp · GitHub

https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L105-L114
generic

winfsp/src/sys/devctl.c at v2.2B4 · winfsp/winfsp · GitHub

https://github.com/winfsp/winfsp/blob/v2.2B4/src/sys/devctl.c#L68-L73
generic

GitHub - winfsp/winfsp: Windows File System Proxy - FUSE for Windows · GitHub

https://github.com/winfsp/winfsp
github_commit

commit b8103265ec63 (winfsp/winfsp)

Fix landed in winfsp/winfsp commit b8103265ec63 — awaiting tagged release

https://github.com/winfsp/winfsp/commit/b8103265ec63fa87ac264c62bb796dbc38376652

Vendor Advisories for CVE-2026-93689(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 18× in last 7d / 38× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-03 22:36 UTCEG score recompute
  2. 2026-10-03 22:36 UTCGHSA enrichment
  3. 2026-10-03 14:26 UTCEPSS rescore
  4. 2026-10-02 21:47 UTCEG score recompute
  5. 2026-10-02 21:47 UTCGHSA enrichment
  6. 2026-10-01 20:58 UTCEG score recompute
  7. 2026-10-01 20:58 UTCGHSA enrichment
  8. 2026-10-01 19:51 UTCEPSS rescore
  9. 2026-09-30 20:08 UTCEG score recompute
  10. 2026-09-30 20:08 UTCGHSA enrichment
  11. 2026-09-30 15:04 UTCEPSS rescore
  12. 2026-09-29 19:19 UTCEG score recompute
  13. 2026-09-29 19:19 UTCGHSA enrichment
  14. 2026-09-28 18:16 UTCEG score recompute
  15. 2026-09-28 18:16 UTCGHSA enrichment
  16. 2026-09-28 13:52 UTCEPSS rescore
  17. 2026-09-28 13:52 UTCEPSS rescore
  18. 2026-09-27 17:25 UTCGHSA enrichment
  19. 2026-09-26 16:35 UTCEG score recompute
  20. 2026-09-26 16:34 UTCGHSA enrichment
  21. 2026-09-26 15:59 UTCEPSS rescore
  22. 2026-09-25 15:40 UTCGHSA enrichment
  23. 2026-09-24 14:51 UTCEG score recompute
  24. 2026-09-24 14:51 UTCGHSA enrichment
  25. 2026-09-24 14:04 UTCEPSS rescore
Show 13 more
  1. 2026-09-23 21:23 UTCGHSA enrichment
  2. 2026-09-22 20:34 UTCEG score recompute
  3. 2026-09-22 20:34 UTCGHSA enrichment
  4. 2026-09-22 16:01 UTCEPSS rescore
  5. 2026-09-21 21:09 UTCEPSS rescore
  6. 2026-09-21 19:55 UTCGHSA enrichment
  7. 2026-09-20 19:05 UTCGHSA enrichment
  8. 2026-09-19 18:16 UTCEG score recompute
  9. 2026-09-19 18:16 UTCGHSA enrichment
  10. 2026-09-18 17:26 UTCEG score recompute
  11. 2026-09-18 16:27 UTCEG score recompute
  12. 2026-09-18 15:24 UTCEG score recompute
  13. 2026-09-18 15:24 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-93689?
CVE-2026-93689 is a medium vulnerability published on September 18, 2026. 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…
When was CVE-2026-93689 disclosed?
CVE-2026-93689 was first published on September 18, 2026, with the most recent update on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-93689 actively exploited?
CVE-2026-93689 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (3rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-93689?
CVE-2026-93689 has a CVSS base score of 5.5 (the CNA's own assessment, by vulncheck; NVD's own analysis pending).
How do I remediate CVE-2026-93689?
A fix for CVE-2026-93689 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-93689 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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