CVE-2023-6606: An out-of-bounds read vulnerability was found in smbCalcSize in fs/smb/client/netmisc.c in the Linux Kernel

Q: How do I fix CVE-2023-6606?

linux kernel: upgrade to 6.7; enterprise linux: mitigate or apply the listed mitigation; enterprise linux eus: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2023-6606 being exploited?

CVE-2023-6606 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2023-6606 affect?

CVE-2023-6606 affects linux kernel, enterprise linux, enterprise linux eus. Severity is high (CVSS 7.1). An out-of-bounds read vulnerability was found in smbCalcSize in fs/smb/client/netmisc.c in the Linux Kernel. This issue could allow a local attacker to crash the system or leak internal kernel information.

Q: How urgent is CVE-2023-6606?

Priority 46/100. High severity; Public exploit reference; On your watchlist

This month

HIGH 7.1WATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2023-6606 is a high-severity flaw (CVSS 7.1) affecting linux kernel, enterprise linux, enterprise linux eus. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An out-of-bounds read vulnerability was found in smbCalcSize in fs/smb/client/netmisc.c in the Linux Kernel. This issue could allow a local attacker to crash the system or leak internal kernel information.

Why this priority

High severity
Public exploit reference
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.1 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.5% (top 56%)
CISA exploited list	No
Weakness	CWE-125
Published	2023-12-08
Last modified	2026-10-14

Publisher (CNA): Red Hat, Inc. · Vendor: linux · redhat

Last updated 2026-10-14 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-12-08 17:15 UTCPublished CVE record published
2026-10-14 23:17 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: >= 6.4.1 and < 6.7 · 6.4 · 6.4 rc4 · 6.4 rc5 · 6.4 rc6 · 6.4 rc7 · 6.7 rc1 · 6.7 rc2

Fixed in: 6.7

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux MITIGATE

Affected: 8.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux eus MITIGATE

Affected: 9.2 · 9.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.2

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux server aus MITIGATE

Affected: 9.2 · 9.4

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.2

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux server for power little endian update services for sap solutions MITIGATE

Affected: 9.2 · 9.2_ppc64le

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.2

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-6606?

linux kernel: upgrade to 6.7; enterprise linux: mitigate or apply the listed mitigation; enterprise linux eus: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-6606 being exploited?

CVE-2023-6606 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-6606 affect?

CVE-2023-6606 affects linux kernel, enterprise linux, enterprise linux eus. Severity is high (CVSS 7.1). An out-of-bounds read vulnerability was found in smbCalcSize in fs/smb/client/netmisc.c in the Linux Kernel. This issue could allow a local attacker to crash the system or leak internal kernel information.

How urgent is CVE-2023-6606?

Priority 46/100. High severity; Public exploit reference; On your watchlist

Software pages

Linux kernel vulnerabilities · SAP vulnerabilities

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References

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