PatchTheCVECVE-2026-70321: Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code
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HIGH 8.8WATCHLISTUPGRADE
CVE-2026-70321 is a high-severity flaw (CVSS 8.8) affecting sharepoint server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Why this priority
- High severity
- On your watchlist
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.8 (High) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | None |
| EPSS exploit chance | 1.7% (top 23%) |
| CISA exploited list | No |
| Weakness | CWE-502 |
| Published | 2026-08-11 |
| Last modified | 2026-10-23 |
Publisher (CNA): Microsoft Corporation · Vendor: microsoft
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
microsoft sharepoint server UPGRADE
Affected: < 16.0.19725.20522
Fixed in: 16.0.19725.20522
Safe to downgrade to: no unaffected older release
1. Check installed version
apt-cache policy sharepoint-server || rpm -q sharepoint-server || sharepoint-server --version
2. UPGRADE to 16.0.19725.20522 (Debian / Ubuntu)
sudo apt update && sudo apt install --only-upgrade sharepoint-server
2. UPGRADE (RHEL / Amazon Linux / Fedora)
sudo dnf upgrade sharepoint-server
Note
Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.
Exact fixes by distribution
Fedora 46 · diffoscope · FIXED · 335-1.fc46 · FEDORA-2026-e4c4cc0856 · source
sudo dnf upgrade --advisory=FEDORA-2026-e4c4cc0856
Microsoft SharePoint Server Subscription Edition · KB5002893 · FIXED · 16.0.19725.20522 · KB5002893 · source
Install KB5002893 via Windows Update, then verify:
Get-HotFix -Id KB5002893
Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Related CVEs
- CVE-2026-70326 HIGH 8.8 UPGRADE Server-side request forgery (ssrf) in Microsoft Office SharePoint allows an authorized attacker to elevate pri
- CVE-2026-57105 HIGH 8.0 UPGRADE Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office Share
- CVE-2026-65660 HIGH 8.8 EXPLOITED UPGRADE Microsoft SharePoint Code Injection Vulnerability