CVE-2026-63520 Public exploit High · 8.1 EPSS 1.0%
Microsoft SharePoint Server Remote Code Execution Vulnerability
Microsoft · Microsoft SharePoint Enterprise Server 2016
Official description · CVE.org
Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Priority scorePatchfirst’s 0 to 100 ranking. It adds points for CISA KEV listing, ransomware use, EPSS, threat reports, public exploit code and CVSS. Every CVE page shows the breakdown. Breakdown
70.1 / 100
- Exploited
- Yes, in VulnCheck KEV
- Reports
- 0
- Tactics
- 0/15
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited 14 days after disclosure. Public exploit code (PoC-in-GitHub) appeared 15 days after disclosure.
- Disclosedday 0
- First seen exploitedVulnCheck KEV evidence+14 days
- Public exploit codePoC-in-GitHub+15 days
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
No techniques linkedNo ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.
What security researchers reported
Not named in any threat report yetAlso mentioned in 8 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.
- EbeeOct2026 Pt113 Oct 2026
- SMTP is the key: BPFDoor and AVERAT hitting the network edge6 Oct 2026
- SMTP is the key: BPFDoor and AVERAT hitting the network edge.3 Oct 2026
- SMTP is the key: BPFDoor and AVERAT hitting the network edge2 Oct 2026
- ThreatsDay: 296K IoT Botnet, 100+ Water Systems Targeted, SharePoint RCE Chain + 27 New Stories27 Aug 2026
- Microsoft SharePoint Unauth RCE Chain: CVE-2026-55040 + CVE-2026-6352027 Aug 2026
- 2 more on OTX