# CVE-2020-9818: Apple iOS, iPadOS, and watchOS Out-of-Bounds Write Vulnerability

Source: https://junglewise.ai/threats/cve-2020-9818-apple-ios-ipados-and-watchos-out-of-bounds-write-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-11-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2020-9818 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2021-11-03

An out-of-bounds write vulnerability in the Mail component of Apple iOS, iPadOS, and watchOS allows for memory modification or application termination. The flaw is triggered when the system processes a maliciously crafted email message and was addressed through improved bounds checking.

Technologies: [Apple iPadOS](https://junglewise.ai/threats/technologies/ipados), [Apple watchOS](https://junglewise.ai/threats/technologies/watchos). Vendors: [Apple](https://junglewise.ai/threats/vendors/apple).

## Quick answers

**Is CVE-2020-9818 exploited in the wild?** Yes. CVE-2020-9818 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2020-9818?** Critical severity, with a CVSS score of 8.8, published 3 November 2021.

**Which products and versions are affected?** Apple iOS < 12.4.7, 13.0 to < 13.5; Apple iPadOS < 13.5; Apple watchOS < 6.2.5.

**Is there a fix for CVE-2020-9818?** A patch was published on 2020-05-20: Fixed in iOS 13.5, iPadOS 13.5, iOS 12.4.7, and watchOS 6.2.5 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2020-9818 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2020-9818?** Check whether you run Apple iPadOS or Apple watchOS. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Apple iOS < 12.4.7, 13.0 to < 13.5
- Apple iPadOS < 13.5
- Apple watchOS < 6.2.5

## Timeline

- 2020-06-09: disclosed: NVD Published Date
- 2020-05-20: patched: Fixed in iOS 13.5, iPadOS 13.5, iOS 12.4.7, and watchOS 6.2.5
- 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2021-11-03: exploited: Reported as exploited in the wild in CISA KEV catalog

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