---
id: "CVE-2023-28204"
kind: "vulnerability"
aliases: ["CVE-2023-28204"]
title: "An out-of-bounds read was addressed with improved input validation"
severity: "medium"
cvss: 6.5
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "Apple Multiple Products", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "apple safari", "fixed": ["16.5"], "affected": "< 16.5", "ecosystem": "vendor"}, {"name": "apple ipados", "fixed": ["15.7.6"], "affected": "< 15.7.6", "ecosystem": "vendor"}, {"name": "apple ipados", "fixed": ["16.5"], "affected": ">= 16.0, < 16.5", "ecosystem": "vendor"}, {"name": "apple iphone os", "fixed": ["15.7.6"], "affected": "< 15.7.6", "ecosystem": "vendor"}, {"name": "apple iphone os", "fixed": ["16.5"], "affected": ">= 16.0, < 16.5", "ecosystem": "vendor"}, {"name": "apple macos", "fixed": ["13.4"], "affected": ">= 13.0, < 13.4", "ecosystem": "vendor"}, {"name": "apple tvos", "fixed": ["16.5"], "affected": "< 16.5", "ecosystem": "vendor"}, {"name": "apple watchos", "fixed": ["9.5"], "affected": "< 9.5", "ecosystem": "vendor"}, {"name": "webkitgtk webkitgtk\\+", "fixed": ["2.42.3"], "affected": "< 2.42.3", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["apple-devices", "exploited", "ios", "ipados", "macos", "safari", "vendor", "webkit"]
not_affected_if: ["unknown"]
published_at: "2023-05-22T00:00:00+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T22:29:04+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-28204", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-28204", "first_seen_at": "2026-10-23T22:29:04+00:00"}]
---

# An out-of-bounds read was addressed with improved input validation

An out-of-bounds read in WebKit, the browser engine used by Safari and iOS, lets a malicious web page make the browser read memory it should not. An attacker can use it to disclose sensitive information.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Apple Multiple Products affected ? fixed ?
- vendor:apple safari affected < 16.5 fixed 16.5
- vendor:apple ipados affected < 15.7.6 fixed 15.7.6
- vendor:apple ipados affected >= 16.0, < 16.5 fixed 16.5
- vendor:apple iphone os affected < 15.7.6 fixed 15.7.6
- vendor:apple iphone os affected >= 16.0, < 16.5 fixed 16.5
- vendor:apple macos affected >= 13.0, < 13.4 fixed 13.4
- vendor:apple tvos affected < 16.5 fixed 16.5
- vendor:apple watchos affected < 9.5 fixed 9.5
- vendor:webkitgtk webkitgtk\+ affected < 2.42.3 fixed 2.42.3

## How to check

Check the OS and Safari versions on each Apple device against Apple's security notes for CVE-2023-28204; unknown which exact builds are fixed in the sources.

## Fix

Update iOS, iPadOS, macOS, tvOS, watchOS and Safari to the latest versions per Apple's vendor instructions.
For non-Apple apps embedding WebKit, unknown which versions are fixed.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-28204
- 2026-10-23T22:29:04+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2023-28204

## From the sources

Apple iOS, iPadOS, macOS, tvOS, watchOS, and Safari WebKit contain an out-of-bounds read vulnerability that may disclose sensitive information when processing maliciously crafted web content. This vulnerability could impact HTML parsers that use WebKit, including but not limited to Apple Safari and non-Apple products which rely on WebKit for HTML processing.

CISA required action: Apply updates per vendor instructions.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_