CVE Intelligence
High Memory corruption exploit reference

CVE-2023-6606 — Kernel: out-of-bounds read vulnerability in smbcalcsize

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.

Published Dec 8, 2023 · Updated Oct 14, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: redhat

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.5% (30-day exploitation probability)+6
  • Technical severity (high)+6
  • CISA SSVC: exploitation "poc"+5

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.53%
ahead of 43% of scored CVEs · Oct 14, 2026
Affects
Linux
Linux Kernel and 11 more
CVSS base
7.1
High · 4 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Proof of concept
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux Kernel, Red Hat Enterprise Linux, Red Hat Enterprise Linux Eus…).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux Kernel version 6.7-rc6version 6.7-rc5version 6.7-rc4version 6.7-rc3version 6.7-rc2≥ 6.4.1 and < 6.7version 6.4version 6.4-rc4
and 4 more version 6.4-rc5version 6.4-rc6version 6.4-rc7version 6.7-rc1
Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux version 9.0version 8.0 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Eus version 9.4version 9.2 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Server Aus version 9.4version 9.2 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions version 9.2version 9.2_ppc64le Vulnerable NIST National Vulnerability Database
Red Hat Red Hat Enterprise Linux 8 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 8.8 Extended Update Support versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 9 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 9.2 Extended Update Support versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Virtualization 4 for Red Hat Enterprise Linux 8 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat RHOL-5.8-RHEL-9 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.1 CVSS 3.1 High 1.8 5.2 secalert@redhat.com via NIST National Vulnerability Database
7.1 CVSS 3.1 High 1.8 5.2 nvd@nist.gov via NIST National Vulnerability Database
7.1 CVSS 3.1 High — — GitHub, Inc. via GitHub Security Advisories
7.1 CVSS 3.1 High — — redhat via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-125 · Out-of-bounds Read

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
endpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · red hat/red hat enterprise linux 8, red hat/red hat enterprise linux 8.6 extended update support, red hat/red hat enterp
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 14, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 14, 2026
  • Affected products added · linux/linux kernel, redhat/enterprise linux, redhat/enterprise linux eus, redhat/enterprise linux server aus, redhat/ent
    Oct 14, 2026 · NIST National Vulnerability Database
  • CVSS changed · 7.1
    Oct 14, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 14, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 14, 2026 · Alertas do Telegram
  • 2023
  • CVE published
    Dec 8, 2023 · redhat

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 14, 2026 – Oct 14, 2026
  • 1× Official description updated · Oct 14, 2026 – Oct 14, 2026

References

17 on the record

Elsewhere on this site

Linux
every CVE for this vendor
Memory corruption
same class
CWE-125
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-110927 Openssh: openssh: a compressed payload can expand past the maximum packet size 9h
  • CVE-2026-110924 Openssh: openssh: gssapi delegated credentials can be stored after a failed authentication 9h
  • CVE-2026-110923 Openssh: openssh: sftp can write outside the destination directory from a server-supplied path 17h
  • CVE-2026-110925 Openssh: openssh: '$' and '\' in a command-line username expand through %u 17h
  • CVE-2026-110926 Openssh: openssh: shared lz77 compression dictionary leaks plaintext across channels 17h
  • CVE-2026-86849 Dpdk: dpdk: integer overflow combined with missing validation leads to host buffer overflow in vhost-crypto 1d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2023-6606 is "Kernel: out-of-bounds read vulnerability in smbcalcsize", rated High. It affects Linux Kernel (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.1 describes technical severity. EPSS 0.53% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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