Applications
CVE-2026-120788
Heap overflow in Excel enabling remote code execution via crafted spreadsheet
Major vulnerability. Microsoft Excel is widely deployed across enterprises; a remote code execution bug in Excel can disrupt many organizations and attract broad exploitation.
- CVSS
- 8.8Highscored by the publisher (CNA)
- Exploited in the wild
- Not knownnot in CISA KEV as of our last sync
- EPSS
- 0.95%chance of exploitation in the next 30 daystop 39% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 10 Nov 2026analysed here 12 Nov 2026
Summary
Impact
Remote code execution over network via crafted Excel file; attacker can run arbitrary code as the user, leading to system compromise and lateral movement.
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
| Product | Affected versions | Vendor says fixed in |
|---|---|---|
| Microsoft Microsoft 365 Apps for Enterprise | >= 16.0.1 and < https://aka.ms/OfficeSecurityReleasesVendor says fixed in: not stated | |
| Microsoft Microsoft Office 365 for Mac | >= 1.0.0 and < 16.115.26110837Vendor says fixed in: not stated | |
| Microsoft Microsoft Office LTSC 2021 | >= 16.0.1 and < 16.0.14334.21048Vendor says fixed in: not stated | |
| Microsoft Microsoft Office LTSC 2024 | >= 16.0.0 and < 16.0.17932.21140Vendor says fixed in: not stated | |
| Microsoft Microsoft Office LTSC for Mac 2021 | >= 16.0.1 and < 16.115.26110837Vendor says fixed in: not stated | |
| Microsoft Microsoft Office LTSC for Mac 2024 | >= 16.0.0 and < 16.115.26110837Vendor says fixed in: not stated | |
| Microsoft Office Online Server | >= 16.0.0.0 and < 16.0.10417.20236Vendor says fixed in: not stated |
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.
Products named in our analysis
- Microsoft Excel (Office)
- Microsoft Office for Windows
Fix and mitigation
Action required
Immediate action required
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Not listed as of our last sync.
- Public exploit code
- None on record in Exploit-DB, Metasploit, Nuclei templates or PoC-in-GitHub.
- CISA SSVC
- exploitation none, automatable no, technical impact totalAssessed by CISA 10 Nov 2026 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
Timeline
- 10 Nov 2026Published
- 10 Nov 2026CISA SSVC assessment: exploitation nonesame day later
- 11 Nov 2026CVE record last updated1 day later
- 12 Nov 2026Analysed by vulneraibility.com1 day later
Common questions
Is CVE-2026-120788 being exploited?
Not confirmed. CVE-2026-120788 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.95% probability of exploitation in the next 30 days.
How severe is CVE-2026-120788?
CVE-2026-120788 is rated High with a CVSS score of 8.8. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-120788?
Yes. A fix has been recorded for CVE-2026-120788. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-120788 affect?
CVE-2026-120788 affects Microsoft Excel (Office), Microsoft Office for Windows. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-120788?
Install Microsoft security update immediately; block or scan untrusted Excel files.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
1 reference in the CVE record, grouped by the tags the record gives them.
Patches (1)
- msrc.microsoft.com /update-guide/vulnerability/CVE-2026-120788
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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