CVE-2026-64392

CRITICALPre-NVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 93% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 5 sources updated this week
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.1Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: use opener credentials for delete-on-close

Delete-on-close can be completed by deferred or durable handle teardown, where no request work is available. Both the base-file unlink and the ADS xattr removal consequently run with the ksmbd worker credentials and can bypass filesystem permission checks.

Run both operations with the credentials captured in struct file when the handle was opened. This preserves the authenticated user's fsuid, fsgid, supplementary groups and capability restrictions at final close.

CVSS v3
9.1
EG Score
9.1(medium)
EG Risk
46(Track)
EG Risk 46/100SSVC: Track

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
Severity91% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
7%
KEV
Not listed

Published

July 25, 2026

Last Modified

July 27, 2026

Advisory Details (5)

Auto-updated Jul 27, 2026
No patch confirmed yet.
generic

ksmbd: use opener credentials for delete-on-close - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/52e2f21911158ec961cd5aae19c56460db382af0
generic

ksmbd: use opener credentials for delete-on-close - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/4b7059974549d278e30fe70e2a4e421f9839817d
generic

ksmbd: use opener credentials for delete-on-close - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/e72c15085b6d86f45d224d98aa75b5cace4aaab9
generic

ksmbd: use opener credentials for delete-on-close - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/18c59109bb6fb816d5102171666f87cf1e29901d
generic

ksmbd: use opener credentials for delete-on-close - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/f08b3f451f12eee4abd8a5981803bc36db84458b

Vendor Advisories for CVE-2026-64392(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 14× 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. 2026-07-27 05:29 UTCEG score recompute
  2. 2026-07-27 05:28 UTCGHSA enrichment
  3. 2026-07-27 05:16 UTCEG score recompute▲ 9.10
  4. 2026-07-27 05:16 UTCGHSA enrichment
  5. 2026-07-27 05:12 UTCMITRE cvelistV5CVSS v3 → 9.1 · severity → CRITICAL
  6. 2026-07-26 14:54 UTCEPSS rescore
  7. 2026-07-26 14:54 UTCEPSS rescore
  8. 2026-07-26 02:49 UTCEG score recompute
  9. 2026-07-26 02:48 UTCGHSA enrichment
  10. 2026-07-25 14:18 UTCEPSS rescore
  11. 2026-07-25 14:18 UTCEPSS rescore
  12. 2026-07-25 10:39 UTCNVD update
  13. 2026-07-25 09:32 UTCEG score recompute
  14. 2026-07-25 09:21 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-64392?
CVE-2026-64392 is a critical vulnerability published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: use opener credentials for delete-on-close Delete-on-close can be completed by deferred or durable handle teardown, where no request work is available. Both the base-file unlink and the ADS xattr removal consequently run…
When was CVE-2026-64392 disclosed?
CVE-2026-64392 was first published in the National Vulnerability Database on July 25, 2026, with the most recent update on July 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64392 actively exploited?
CVE-2026-64392 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 92.6% of all scored CVEs.
What is the CVSS score of CVE-2026-64392?
CVE-2026-64392 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2026-64392?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64392, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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