No exploitation reportedFix available

CVE-2023-38427

Q: Is CVE-2023-38427 actively exploited?

Active exploitation of CVE-2023-38427 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2023-38427?

CVE-2023-38427 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

No exploitation reported by the sources we read.

Published2023-07-18
Fixed in6.3.8 · 6.1.34 · 5.15.145
WeaknessCWE-125 · CWE-191

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

An issue was discovered in the Linux kernel before 6.3.8. fs/smb/server/smb2pdu.c in ksmbd has an integer underflow and out-of-bounds read in deassemble_neg_contexts.

Timeline

dates in UTC

2023-07-1800:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-38427?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-38427?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Linux linux kernel

Branch	Affected	Fixed in	Source
6.x	≥ 6.2, < 6.3.8	6.3.8	NVD
6.1	≥ 5.16, < 6.1.34	6.1.34	NVD
5.15	≥ 5.15, < 5.15.145	5.15.145	NVD

Netapp h300s

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

Netapp h410s

Branch	Affected	Fixed in	Source
—	all versions	no fix published	NVD

2 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Linux linux kernel to 6.3.8 · 6.1.34 · 5.15.145

Advisories and patches

cdn.kernel.orgRelease Notes
git.kernel.orgPatch

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2025-04-23
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.19.82025-05-02
NVDCVSS 3.19.8read 2026-10-23
CISA-ADPweakness (CWE)CWE-125, CWE-1912025-05-02
NVDweakness (CWE)CWE-125, CWE-191read 2026-10-23
FIRST EPSSEPSS score1.2 %2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published: 2023-07-18
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2023-38427?

An issue was discovered in the Linux kernel before 6.3.8. fs/smb/server/smb2pdu.c in ksmbd has an integer underflow and out-of-bounds read in deassemble_neg_contexts.

Is CVE-2023-38427 actively exploited?

Active exploitation of CVE-2023-38427 has not been confirmed. Its EPSS score was 1.2% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-38427?

CVE-2023-38427 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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