Microsoft Office PowerPoint: Heap-based buffer overflow allows code execution
Summary
A heap-based buffer overflow in Microsoft Office PowerPoint allows an unauthorized attacker to execute code over a network. Exploitation requires that a user opens a crafted presentation, for example from an email attachment, download or shared link. The CVSS 3.1 base score is 7.5 (High), with high attack complexity and required user interaction.
Affected
- Microsoft 365 Apps for Enterprise: 16.0.1 up to the fixed build named at aka.ms/OfficeSecurityReleases
- Office LTSC 2021: 16.0.1 to before 16.0.14334.20974
- Office LTSC 2024: 16.0.0 to before 16.0.17932.21056
- Office 365 for Mac and Office LTSC for Mac 2021/2024: before 16.114.26101123 according to the CVE record
Fixed in
- Office LTSC 2021: 16.0.14334.20974
- Office LTSC 2024: 16.0.17932.21056
- Microsoft 365 Apps for Enterprise: Unknown (build not confirmed in the sources; see the MSRC advisory)
- Mac: 16.114.26101123 as the upper bound of the CVE record range; confirm in the MSRC advisory
Workaround
Unknown. No workaround or mitigation was found in the sources, so the security update is the fix.
Exploitation
- Microsoft's SSVC assessment in the CVE record: exploitation none, not automatable, total technical impact.
- No public proof of concept or exploit was found in the research.
- No CISA KEV listing was found in the searches; please verify.
- EPSS was about 0.5% in mid-October 2026.
Our recommendation
- Install the October 2026 Office security updates on all affected Microsoft 365, LTSC and Mac installations; check LTSC 2021 and 2024 manually.
- Verify installed build numbers against the MSRC advisory before rollout.
- Patch together with the other Office heap overflows fixed in the same update.
- Be cautious with presentations from unknown senders and keep mail and file-sharing gateway filtering active.
- Monitor for exploitation reports and raise the priority if Microsoft marks the vulnerability as exploited.
Information from Microsoft (Patch Tuesday October 2026)
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Update Guide: CVE-2026-105599 msrc.microsoft.com
- Vulners: MSCVE CVE-2026-105599 (Microsoft ranges) vulners.com
- Microsoft Office for Mac release notes learn.microsoft.com
- Strix: CVE-2026-105599 (CNA data) www.strix.ai
- Rapid7: October 2026 Patch Tuesday review www.rapid7.com
- Vulners: NVD CVE-2026-105599 vulners.com
- Vulners: Nessus Office C2R October 2026 check vulners.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 2 Nov 2026, 19:36.
Original description (NVD)
Heap-based buffer overflow in Microsoft Office PowerPoint 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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