CVE-2023-40420VulnerabilityPublished 26 Sep 2023Updated 4 Nov 2025

CVE-2023-40420: Apple iOS and iPadOS · Processing web content may lead to a denial-of-service

Affects Apple iOS and iPadOSSource CVE Database V5

Not known to be exploited.

Data as of 26 Oct 2026, 06:26 UTC

Severity

Medium

Rated Medium by the CNA (apple) · No CVSS score from NVD or the CNA

EPSS: 1.4% chance of exploitation in 30 days – higher than 72% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 26 Sep 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 2026-10-26.

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

Apple has released official fixes for this vulnerability in macOS Ventura 13.6, tvOS 17, iOS 16.7, iPadOS 16.7, macOS Monterey 12.7, watchOS 10, iOS 17, iPadOS 17, and macOS Sonoma 14. Users and administrators should apply these updates to remediate the issue.

Description

CVE-2023-40420 is a vulnerability in Apple iOS and iPadOS where processing web content may lead to a denial-of-service condition. The issue was addressed by Apple through improved memory handling. Fixes have been released in multiple Apple operating system versions including macOS Ventura 13.6, tvOS 17, iOS 16.7, iPadOS 16.7, macOS Monterey 12.7, watchOS 10, iOS 17, iPadOS 17, and macOS Sonoma 14.

Impact

Successful exploitation of this vulnerability may cause a denial-of-service condition on affected Apple devices by processing crafted web content. There is no indication of code execution or data breach. No known exploits in the wild have been reported.

Summary

This vulnerability involves a denial-of-service risk triggered by processing web content on Apple devices running iOS and iPadOS. The root cause was related to memory handling deficiencies, which Apple has corrected in several OS updates. The vulnerability affects multiple Apple platforms and has been resolved in the specified fixed versions.

References

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 25 Oct 2026, 21:58 UTC

Technical details

References

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