PatchTheCVECVE-2026-63520: Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code over
CVE-2026-63520 is a high-severity flaw (CVSS 8.1) affecting sharepoint server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
Why this priority
- High severity
- Remotely exploitable, no login, no user action
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.1 (High) |
| Attack vector | Network (remote) |
| Attack complexity | High |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 1.0% (top 39%) |
| CISA exploited list | No |
| Weakness | CWE-20 |
| Published | 2026-08-11 |
| Last modified | 2026-08-13 |
Last updated 2026-08-13 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Advisories and coverage
Research and news
- VulnCheck Blog: Exploiting SharePoint: CVE-2026-55040 and CVE-2026-63520 RCE Chain 2026-08-24
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-63520?
sharepoint server: upgrade to 16.0.19725.20522. Exact commands for each OS are on this page.
Is CVE-2026-63520 being exploited?
CVE-2026-63520 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-63520 affect?
CVE-2026-63520 affects sharepoint server. Severity is high (CVSS 8.1). Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.
How urgent is CVE-2026-63520?
Priority 54/100. High severity; Remotely exploitable, no login, no user action; On your watchlist
Software pages
SharePoint vulnerabilities · Microsoft Office vulnerabilities
Related CVEs
- CVE-2026-32201 MEDIUM 6.5 EXPLOITED UPGRADE Microsoft SharePoint Server Improper Input Validation Vulnerability
- CVE-2026-20945 MEDIUM 4.6 UPGRADE Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office Share
- CVE-2026-33112 HIGH 8.8 UPGRADE Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code
- CVE-2026-33110 HIGH 8.8 UPGRADE Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code
- CVE-2026-35439 HIGH 8.8 UPGRADE Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code