CVE-2026-64397

CRITICALPre-NVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2026-07-25. a secondary CVSS source baseline 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
Trending — 4 sources updated this week
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

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

ksmbd: serialize QUERY_DIRECTORY requests per file

smb2_query_dir() stores a pointer to its stack-allocated private data in the ksmbd_file readdir_data. Concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this pointer while an iterate_dir() callback is still using it, resulting in a stack use-after-free.

Add a per-file mutex and hold it while accessing the shared directory enumeration state. The lock covers scan restart, dot entry state, readdir_data setup and iteration, and response construction. This prevents another request from replacing readdir_data.private before the current request has finished using it and also serializes the shared file position.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
49(Track)
EG Risk 49/100SSVC: 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
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
40%
KEV
Not listed

Published

July 25, 2026

Last Modified

September 4, 2026

Advisory Details (6)

Auto-updated Sep 11, 2026
No patch confirmed yet.
generic

ksmbd: serialize QUERY_DIRECTORY requests per file - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/fd22b039a5a05bc1d6818e9dcd1001fb432a829d
generic

ksmbd: serialize QUERY_DIRECTORY requests per file - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/be6d26bf27499977c746abc163659915082348d8
generic

ksmbd: serialize QUERY_DIRECTORY requests per file - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/a1d5d31cad593ea5e1b637f2f39c9ef6d09d1199
generic

ksmbd: serialize QUERY_DIRECTORY requests per file - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/64dac2d486ec1eb18dc00968b16a230b6b75ec24
generic

ksmbd: serialize QUERY_DIRECTORY requests per file - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/2a64dbf9c739ddf7a25a066507597bf89f8f73d2
generic

ksmbd: serialize QUERY_DIRECTORY requests per file - kernel/git/stable/linux.git - Linux kernel stable tree

https://git.kernel.org/stable/c/1426fd79102539bc0ab5c8fced047ad4313b9908

Vendor Advisories for CVE-2026-64397(2)

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

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oem-7.0 (7.0.0-1013.13) @ resolute2026-09-15ubuntu
ubuntulinux-tools-gcp-edge (7.0.0-1011.11~24.04.1) @ noble2026-09-15ubuntu
ubuntulinux-virtual-hwe-26.04-edge (7.0.0-31.31) @ resolute2026-09-15ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1018.18~24.04.1) @ noble2026-09-15ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Debian:12(2)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (55 versions)6.1.180-1—
linux-6.12—6.12.100-1~deb12u1—
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux-6.16.1.106-3~deb11u1 ... 6.1.177-1~deb11u1 (22 versions)6.1.180-1~deb11u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.95-1~bpo12+1 (30 versions)6.12.96-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.1~rc7-1~exp1 (158 versions)7.1.4-1—

Weakness Classification(1)

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

All Vendor Advisories

(4)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 60× in last 7d / 191× 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.

Showing the most recent 100 of 382 total refreshes for this CVE.

  1. 2026-09-15 09:23 UTCEG score recompute
  2. 2026-09-15 09:23 UTCVendor advisory
  3. 2026-09-15 09:23 UTCGHSA enrichment
  4. 2026-09-14 16:07 UTCVendor advisory
  5. 2026-09-14 16:07 UTCGHSA enrichment
  6. 2026-09-14 12:23 UTCVendor advisory
  7. 2026-09-14 12:23 UTCGHSA enrichment
  8. 2026-09-14 08:38 UTCVendor advisory
  9. 2026-09-14 08:38 UTCGHSA enrichment
  10. 2026-09-14 04:54 UTCVendor advisory
  11. 2026-09-14 04:54 UTCGHSA enrichment
  12. 2026-09-14 01:09 UTCVendor advisory
  13. 2026-09-14 01:09 UTCGHSA enrichment
  14. 2026-09-13 21:25 UTCEG score recompute
  15. 2026-09-13 21:25 UTCVendor advisory
  16. 2026-09-13 21:25 UTCGHSA enrichment
  17. 2026-09-13 15:22 UTCVendor advisory
  18. 2026-09-13 15:22 UTCGHSA enrichment
  19. 2026-09-13 11:27 UTCVendor advisory
  20. 2026-09-13 11:27 UTCGHSA enrichment
  21. 2026-09-13 07:43 UTCVendor advisory
  22. 2026-09-13 07:43 UTCGHSA enrichment
  23. 2026-09-13 03:59 UTCVendor advisory
  24. 2026-09-13 03:59 UTCGHSA enrichment
  25. 2026-09-13 00:14 UTCVendor advisory
Show 75 more
  1. 2026-09-13 00:14 UTCGHSA enrichment
  2. 2026-09-12 20:29 UTCVendor advisory
  3. 2026-09-12 20:29 UTCGHSA enrichment
  4. 2026-09-12 16:44 UTCEG score recompute
  5. 2026-09-12 16:44 UTCVendor advisory
  6. 2026-09-12 16:44 UTCGHSA enrichment
  7. 2026-09-12 12:58 UTCVendor advisory
  8. 2026-09-12 12:58 UTCGHSA enrichment
  9. 2026-09-12 09:13 UTCVendor advisory
  10. 2026-09-12 09:13 UTCGHSA enrichment
  11. 2026-09-12 04:59 UTCVendor advisory
  12. 2026-09-12 04:59 UTCGHSA enrichment
  13. 2026-09-12 00:45 UTCVendor advisory
  14. 2026-09-12 00:45 UTCGHSA enrichment
  15. 2026-09-11 20:27 UTCVendor advisory
  16. 2026-09-11 20:27 UTCGHSA enrichment
  17. 2026-09-11 16:22 UTCEG score recompute
  18. 2026-09-11 16:22 UTCVendor advisory
  19. 2026-09-11 16:22 UTCGHSA enrichment
  20. 2026-09-11 14:53 UTCEPSS rescore
  21. 2026-09-11 09:37 UTCEPSS rescore
  22. 2026-09-11 07:09 UTCVendor advisory
  23. 2026-09-11 07:09 UTCGHSA enrichment
  24. 2026-09-11 02:13 UTCVendor advisory
  25. 2026-09-11 02:13 UTCGHSA enrichment
  26. 2026-09-10 20:51 UTCVendor advisory
  27. 2026-09-10 20:51 UTCGHSA enrichment
  28. 2026-09-10 13:18 UTCEG score recompute
  29. 2026-09-10 13:18 UTCVendor advisory
  30. 2026-09-10 13:18 UTCGHSA enrichment
  31. 2026-09-09 12:20 UTCVendor advisory
  32. 2026-09-09 12:20 UTCGHSA enrichment
  33. 2026-09-09 08:35 UTCEG score recompute
  34. 2026-09-09 08:35 UTCVendor advisory
  35. 2026-09-09 08:35 UTCGHSA enrichment
  36. 2026-09-08 22:01 UTCEPSS rescore
  37. 2026-09-08 00:58 UTCVendor advisory
  38. 2026-09-08 00:58 UTCGHSA enrichment
  39. 2026-09-07 21:14 UTCEG score recompute
  40. 2026-09-07 21:14 UTCVendor advisory
  41. 2026-09-07 21:14 UTCGHSA enrichment
  42. 2026-09-07 16:01 UTCEPSS rescore
  43. 2026-09-06 15:40 UTCEG score recompute
  44. 2026-09-06 15:40 UTCGHSA enrichment
  45. 2026-09-06 13:47 UTCEPSS rescore
  46. 2026-09-06 11:43 UTCGHSA enrichment
  47. 2026-09-06 07:58 UTCGHSA enrichment
  48. 2026-09-06 02:49 UTCGHSA enrichment
  49. 2026-09-05 23:04 UTCGHSA enrichment
  50. 2026-09-05 19:20 UTCEG score recompute
  51. 2026-09-05 19:20 UTCGHSA enrichment
  52. 2026-09-05 15:31 UTCEPSS rescore
  53. 2026-09-05 09:46 UTCGHSA enrichment
  54. 2026-09-05 06:01 UTCGHSA enrichment
  55. 2026-09-04 15:03 UTCEG score recompute
  56. 2026-09-04 15:02 UTCGHSA enrichment
  57. 2026-09-04 12:40 UTCEG score recompute
  58. 2026-09-04 12:39 UTCGHSA enrichment
  59. 2026-09-04 05:07 UTCEPSS rescore
  60. 2026-09-02 14:12 UTCEPSS rescore
  61. 2026-09-01 23:13 UTCEG score recompute
  62. 2026-09-01 23:13 UTCGHSA enrichment
  63. 2026-09-01 13:54 UTCEPSS rescore
  64. 2026-09-01 04:40 UTCEPSS rescore
  65. 2026-08-31 06:45 UTCGHSA enrichment
  66. 2026-08-31 02:27 UTCGHSA enrichment
  67. 2026-08-30 22:42 UTCEG score recompute
  68. 2026-08-30 22:42 UTCGHSA enrichment
  69. 2026-08-30 19:17 UTCEPSS rescore
  70. 2026-08-30 18:58 UTCGHSA enrichment
  71. 2026-08-30 15:14 UTCGHSA enrichment
  72. 2026-08-30 11:20 UTCGHSA enrichment
  73. 2026-08-30 07:35 UTCGHSA enrichment
  74. 2026-08-30 03:50 UTCEG score recompute
  75. 2026-08-30 03:50 UTCGHSA enrichment

Frequently asked(5)

What is CVE-2026-64397?
CVE-2026-64397 is a critical vulnerability published on July 25, 2026. In the Linux kernel, the following vulnerability has been resolved: ksmbd: serialize QUERY_DIRECTORY requests per file smb2querydir() stores a pointer to its stack-allocated private data in the ksmbdfile readdirdata. Concurrent QUERY_DIRECTORY requests using the same file handle can overwrite this…
When was CVE-2026-64397 disclosed?
CVE-2026-64397 was first published in the National Vulnerability Database on July 25, 2026, with the most recent update on September 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-64397 actively exploited?
CVE-2026-64397 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 60.2% of all scored CVEs.
What is the CVSS score of CVE-2026-64397?
CVE-2026-64397 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2026-64397?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-64397, 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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