Vulnerability · CVE-2023-35311
Microsoft Outlook Security Feature Bypass Vulnerability
Published Jul 11, 2023 · catalog updated Oct 8, 2026 · Microsoft Outlook
Patch now
CVE-2023-35311 is in the CISA known-exploited catalog, due Aug 1, 2023. Confirm Microsoft Outlook against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Gaps on this record
- No version range is stored. A customer cannot check an installed version against this record.
- Severity
- High8.8
- Known exploitation
- CISA KEV and VulnCheck KEV
- EPSS
- 15.52%
- Remediation
- Remediation guidance
- Affected products
- cpe microsoft/365 apps · cpe microsoft/office 2019 · cpe microsoft/office 2021 · cpe microsoft/outlook · vendor Microsoft Outlook
Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- cpe microsoft/365 appsversion unspecified
- cpe microsoft/office 2019version unspecified
- cpe microsoft/office 2021version unspecified
- cpe microsoft/outlook2013
- cpe microsoft/outlook2016
- vendor Microsoft Outlookversion unspecified
How to fix CVE-2023-35311
Recommended remediation
Apply updates per vendor instructions or discontinue use of the product if updates are unavailable. CISA due date Aug 1, 2023.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
CVE-2023-35311 is in the CISA known-exploited catalog, due Aug 1, 2023. Confirm Microsoft Outlook against the vendor advisory and apply that fix. The CVSS score does not change the priority.
Which versions are affected?
Compare what you have installed with 2013, 2016. Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
What should an analyst verify?
CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition. EPSS 15.52%. The CISA KEV listing is the exploitation evidence. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jul 11, 2023 · Catalog
Detected
Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt.
Jul 11, 2023 · CISA KEV
Known exploited
Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
Aug 1, 2023 · CISA KEV
Remediation due
Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
Oct 8, 2026 · Catalog
Updated
Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt.
Sources
- CISA KEVConfirmed exploitationCVE-2023-35311
Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt.
cisa.gov - CVE.orgVulnerability recordCVE-2023-35311
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2023-35311
30-day exploitation probability 15.5%
first.org - NIST NVDVulnerability recordCVE-2023-35311
Microsoft Outlook Security Feature Bypass Vulnerability
nvd.nist.gov - VulnCheck KEVConfirmed exploitationCVE-2023-35311
Microsoft Outlook contains a security feature bypass vulnerability that allows an attacker to bypass the Microsoft Outlook Security Notice prompt.
vulncheck.com
References
Freshness
Last verified in this catalog Oct 17, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.