VulnerabilityPublished 29 Jul 2024Updated 2 Apr 2026

CVE-2024-40816: Apple macOS · Out-of-bounds Read

Affects Apple macOSSource CVE Database V5

Not known to be exploited · CVSS 5.5 Medium · fixed in 12.7.6 : update Apple macOS when convenient.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 3.1 base score

5.5Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 12.7.6

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

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

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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 29 Jul 2024
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 26 Oct 2026.

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 or the CVSS exploit maturity 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

Affected software

Product	Affected	Fixed in
Apple macOS	Affected =0	Fixed in–

AI-suggested

To mitigate CVE-2024-40816, organizations should promptly apply the security updates released by Apple for macOS Monterey 12.7.6, Sonoma 14.6, and Ventura 13.6.8 or later versions that include the fix. Beyond patching, organizations should enforce strict local access controls to limit the number of users with local login privileges, reducing the attack surface. Implementing endpoint security solutions that monitor for unusual system behavior or unauthorized local access can help detect exploitation attempts. Regularly auditing user accounts and removing unnecessary local accounts can further reduce risk. Additionally, educating users about the risks of local access and maintaining strong physical security controls to prevent unauthorized device access are critical. For environments where uptime is critical, consider implementing system monitoring and automated recovery mechanisms to quickly respond to unexpected shutdowns. Finally, maintain up-to-date backups to mitigate potential data loss from abrupt system interruptions.

Description

An out-of-bounds read was addressed with improved input validation. This issue is fixed in macOS Monterey 12.7.6, macOS Sonoma 14.6, macOS Ventura 13.6.8. A local attacker may be able to cause unexpected system shutdown.

Impact

The primary impact of CVE-2024-40816 is on system availability, as it allows a local attacker to cause unexpected shutdowns of affected macOS systems. This can disrupt business operations, especially in environments relying on continuous uptime such as servers, workstations in critical infrastructure, or enterprise environments. Although confidentiality and integrity are not compromised, the denial-of-service effect can lead to productivity loss, potential data loss if unsaved work is interrupted, and increased operational costs due to system downtime and recovery efforts. Organizations with multi-user macOS environments or those that allow local access to untrusted users are particularly vulnerable. The medium severity rating reflects the balance between the limited attack vector (local access required) and the impactful outcome (system shutdown). The absence of known exploits reduces immediate risk but does not eliminate the potential for future exploitation. Overall, the threat is significant for organizations that depend heavily on macOS systems for critical tasks and cannot tolerate unexpected outages.

CWE-125Out-of-bounds Read (opens in a new tab)
Base weaknessCWE Top 25 (2025): #8
The product reads data past the end, or before the beginning, of the intended buffer.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design · Language Selection
Use a language that provides appropriate memory abstractions.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Overread Buffers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 2 Apr 2026, 23:31 UTC

WeaknessesCWE-125

Technical details

References

Community reviews

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