CVE-2023-39192VulnerabilityPublished 9 Oct 2023Updated 8 Nov 2025

CVE-2023-39192: Red Hat Enterprise Linux 8 · Out-of-bounds Read

Affects Red Hat Enterprise Linux 8Source CVE Database V5

Not known to be exploited · CVSS 6.7 Medium.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

6.7Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:L

Attack Vector: Local
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Changed
Confidentiality: High
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Oct 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

To mitigate CVE-2023-39192, European organizations should: 1) Apply the official patches or kernel updates provided by Red Hat as soon as they become available to ensure the xt_u32 module properly validates input sizes. 2) Restrict local privileged access strictly to trusted administrators and processes, minimizing the number of users with elevated permissions on Red Hat Enterprise Linux 8 systems. 3) Implement robust privilege escalation prevention controls and monitor for suspicious local activity that could indicate attempts to gain elevated privileges. 4) Use kernel hardening features such as SELinux or AppArmor to limit the impact of potential exploits. 5) Employ system integrity monitoring and kernel crash detection tools to quickly identify and respond to abnormal system behavior. 6) In containerized or multi-tenant environments, isolate workloads and limit capabilities to reduce the risk of local privilege abuse. 7) Regularly audit firewall and Netfilter configurations to ensure no unauthorized modifications that could facilitate exploitation. These steps go beyond generic advice by focusing on access control, monitoring, and environment-specific hardening tailored to the nature of this kernel vulnerability.

Description

A flaw was found in the Netfilter subsystem in the Linux kernel. The xt_u32 module did not validate the fields in the xt_u32 structure. This flaw allows a local privileged attacker to trigger an out-of-bounds read by setting the size fields with a value beyond the array boundaries, leading to a crash or information disclosure.

Impact

For European organizations, this vulnerability poses a risk primarily in environments where multiple users or containers share the same Red Hat Enterprise Linux 8 hosts, such as data centers, cloud providers, and enterprise servers. An attacker who gains local privileged access—through privilege escalation or insider threat—could exploit this flaw to cause kernel crashes, leading to denial of service, or potentially leak sensitive kernel memory contents, risking confidentiality breaches. This could disrupt critical services, especially in sectors like finance, telecommunications, healthcare, and government where Red Hat Enterprise Linux 8 is prevalent. The confidentiality impact is significant because kernel memory may contain sensitive information, including cryptographic keys or user data. However, the requirement for local privileged access limits the attack surface, making remote exploitation unlikely without prior compromise. The availability impact is limited to potential crashes, which could cause temporary service outages. Integrity is not affected by this vulnerability. Organizations relying heavily on Red Hat Enterprise Linux 8 for critical infrastructure should consider this a moderate risk that requires timely remediation to prevent potential exploitation in complex attack chains.

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 8 Nov 2025, 07:34 UTC

Technical details

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