Microsoft Office Outlook: Remote code execution via heap-based buffer overflow
Summary
A heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network. The attack requires user interaction, such as opening a crafted message or file, and high attack complexity. A successful attack would give the attacker high impact on confidentiality, integrity and availability on the affected user's system.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 before the build listed on the Microsoft Office security release page (aka.ms/OfficeSecurityReleases)
- Microsoft Office LTSC 2021: 16.0.1 before 16.0.14334.21048
- Microsoft Office LTSC 2024: 16.0.0 before 16.0.17932.21140
- Classic Outlook versions such as Outlook 2016: Unknown.
Fixed in
- Microsoft 365 Apps for Enterprise: Unknown (fixed build not stated in the CVE record; check the MSRC advisory)
- Microsoft Office LTSC 2021: 16.0.14334.21048 or later
- Microsoft Office LTSC 2024: 16.0.17932.21140 or later
Workaround
Unknown. No vendor-published workaround was found.
Exploitation
- Exploited in the wild: no evidence found.
- Public proof of concept: none found.
- Not listed in CISA KEV.
- CISA SSVC: Exploitation none, Automatable no, Technical Impact total.
Our recommendation
- Install the November 2026 Office security updates on all Microsoft 365 Apps and Office LTSC 2021/2024 installations with Outlook, with high priority because of the email delivery vector.
- Check the exact Microsoft 365 build number against the MSRC advisory, as the CVE record does not state the fixed build.
- Remind users not to open unexpected attachments or links, and monitor for suspicious Outlook activity until patching is complete.
Information from Microsoft (Patch Tuesday November 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-119995 msrc.microsoft.com
- CVE.org record CVE-2026-119995 www.cve.org
- Strix CVE-2026-119995 (NVD status mirror) www.strix.ai
- CVE Threat Intelligence CVE-2026-119995 cve.threatint.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 05:24.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office Outlook allows an unauthorized attacker to execute code over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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