Widely used Microsoft Office; local RCE risk could disrupt many orgs.
CVE-2026-45456
Office type confusion enables local code execution.
Is CVE-2026-45456 being exploited?
Not confirmed. CVE-2026-45456 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 0.44% probability of exploitation in the next 30 days.
How severe is CVE-2026-45456?
CVE-2026-45456 is rated High with a CVSS score of 8.4. 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-2026-45456?
Yes. A fix has been recorded for CVE-2026-45456. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-45456 affect?
CVE-2026-45456 affects Microsoft Office. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-45456?
Apply updates when released; enable auto-updates and restrict macros.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local RCE: attacker can execute arbitrary code on the affected host via Office type confusion.
Monitor only
- affected>= 16.0.1 and < https://aka.ms/OfficeSecurityReleases
- affected>= 19.0.0 and < https://aka.ms/OfficeSecurityReleases
- affected>= 1.0.0 and < 16.110.26061317
- affected>= 16.0.1 and < https://aka.ms/OfficeSecurityReleases
- affected>= 16.0.0 and < https://aka.ms/OfficeSecurityReleases
- affected>= 16.0.1 and < 16.110.26061317
- affected>= 16.0.0 and < 16.110.26061317
- affected>= 16.0.0 and < 16.0.5556.1005
- affected>= 16.0.0 and < 16.0.10417.20153
- affected>= 16.0.0 and < 16.0.19725.20384
- affected>= 16.0.1 and < 16.0.5556.1000
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.