CVE-2023-38431

CRITICALNVD 9.19.1—
EchelonGraph scoreMEDIUM confidence

Score 9.1 from GitHub Security Advisory (severity: CRITICAL) published 2023-07-18. NVD baseline CVSS 9.1; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.1EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 9.1Exploit: None knownExposed: 0

A fix is available — apply it.

An issue was discovered in the Linux kernel before 6.3.8. fs/smb/server/connection.c in ksmbd does not validate the relationship between the NetBIOS header's length field and the SMB header sizes, via pdu_size in ksmbd_conn_handler_loop, leading to an out-of-bounds read.

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%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
65%
KEV
Not listed

Published

July 18, 2023

Last Modified

November 21, 2024

Advisory Details (3)

Auto-updated Jul 21, 2026
No patch confirmed yet.
generic

NetApp Product Security

https://security.netapp.com/advisory/ntap-20230824-0011/
generic

ksmbd: check the validation of pdu_size in ksmbd_conn_handler_loop - kernel/git/torvalds/linux.git - Linux kernel source tree

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/smb/server?id=368ba06881c395f1c9a7ba22203cf8d78b4addc0
generic
https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.3.8

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-virtual-hwe-20.04-edge (5.15.0.102.99) @ jammy2026-05-24ubuntu
ubuntulinux-virtual-hwe-22.04-edge (6.2.0.34.34) @ lunar2026-05-24ubuntu
ubuntulinux-tools-nvidia-hwe-22.04-edge (6.2.0.1011.13) @ jammy2026-05-24ubuntu
ubuntulinux-tools-aws-lts-22.04 (5.15.0.1057.58) @ jammy2026-05-24ubuntu

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

(3 across 3 ecosystems)
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.27-16.1.37-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux—6.3.11-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux—6.3.11-1—

Weakness Classification(1)

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

All Vendor Advisories

(5)

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 7× in last 7d / 28× 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 162 total refreshes for this CVE.

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

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2023-38431?
CVE-2023-38431 is a critical vulnerability published on July 18, 2023. An issue was discovered in the Linux kernel before 6.3.8. fs/smb/server/connection.c in ksmbd does not validate the relationship between the NetBIOS header's length field and the SMB header sizes, via pdusize in ksmbdconnhandlerloop, leading to an out-of-bounds read.
When was CVE-2023-38431 disclosed?
CVE-2023-38431 was first published in the National Vulnerability Database on July 18, 2023, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2023-38431 actively exploited?
CVE-2023-38431 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 35.0% of all scored CVEs.
What is the CVSS score of CVE-2023-38431?
CVE-2023-38431 has a CVSS v3 base score of 9.1 (NVD).
How do I remediate CVE-2023-38431?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-38431, 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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