# CVE-2023-35311: Microsoft Outlook Security Feature Bypass Vulnerability

Source: https://junglewise.ai/threats/cve-2023-35311-microsoft-outlook-security-feature-bypass-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-07-11. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2023-35311 · Severity: critical · CVSS 8.8 · Exploited in the wild · Published 2023-07-11

Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt. The flaw is related to a Time-of-check Time-of-use (TOCTOU) race condition (CWE-367).

Technologies: [Microsoft Outlook](https://junglewise.ai/threats/technologies/outlook). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2023-35311 exploited in the wild?** Yes. CVE-2023-35311 is known to be exploited in the wild, first recorded on 11 July 2023. Treat it as urgent.

**How severe is CVE-2023-35311?** Critical severity, with a CVSS score of 8.8, published 11 July 2023.

**Which products and versions are affected?** Microsoft Outlook 2013 Service Pack 1; Microsoft Outlook 2016; Microsoft Office 2019; Microsoft Office LTSC 2021; and 1 more.

**Is there a fix for CVE-2023-35311?** A patch was published on 2023-07-11. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2023-35311 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2023-35311?** Check whether you run Microsoft Outlook. 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

- Microsoft Outlook 2013 Service Pack 1
- Microsoft Outlook 2016
- Microsoft Office 2019
- Microsoft Office LTSC 2021
- Microsoft Microsoft 365 Apps for Enterprise

## Timeline

- 2023-07-11: disclosed
- 2023-07-11: patched
- 2023-07-11: kev added: Added to CISA Known Exploited Vulnerabilities Catalog
- 2023-07-11: exploited: Reported as exploited in the wild at time of publication.

## Related threats

- [Microsoft Office Outlook user warning spoofing vulnerability](https://junglewise.ai/threats/cve-2026-124194-microsoft-office-outlook-missing-user-interaction-for)
- [Microsoft Outlook heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-123384-heap-based-buffer-overflow-in-microsoft-office-outlook-allows-an)
- [Microsoft Outlook heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-123380-heap-based-buffer-overflow-in-microsoft-office-outlook-allows-an)
- [Microsoft Office Outlook heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-123377-heap-based-buffer-overflow-in-microsoft-office-outlook-allows-an)
- [Microsoft Office Outlook remote code execution](https://junglewise.ai/threats/cve-2026-70125-microsoft-office-outlook-remote-code-execution-vulnerability)