Microsoft SharePoint is widely deployed in enterprises; an authenticated RCE can lead to broad infrastructure compromise and data theft, making this high-impact and newsworthy.
CVE-2026-65665
Authenticated remote code execution in Microsoft SharePoint via unsafe deserialization.
Is CVE-2026-65665 being exploited?
Not confirmed. CVE-2026-65665 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 2.8% probability of exploitation in the next 30 days.
How severe is CVE-2026-65665?
CVE-2026-65665 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-2026-65665?
Yes. A fix has been recorded for CVE-2026-65665. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-65665 affect?
CVE-2026-65665 affects Microsoft Office SharePoint. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-65665?
Apply vendor patch immediately; restrict SharePoint access, isolate affected servers, and monitor logs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated attacker can trigger remote code execution on SharePoint servers, enabling system compromise, lateral movement, and data exfiltration.
Immediate action required
- affected>= 16.0.0 and < 16.0.10417.20198
- affected>= 16.0.0 and < 16.0.19725.20522
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.