Intel

CVE-2026-70321

sharepoint_server: Deserialization of Untrusted Data (CVE-2026-70321)

highEPSS 1.7%

Affected

  • microsoft/sharepoint_server lt *..16.0.19725.20522

Description

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Source: BSI WID PortalBSI CSAFcvelistv5NVD (NIST)Microsoft Security Update Guide

Affected products

The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

microsoftsharepoint_server
16.0.19725.20522fixed from 16.0.19725.20522

Metrics

XIEM Effective CVSS
8.8
Source: nvd-v3
EPSS percentile
76.4 %
High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
KEV status
—
Show all metrics
Severity
high
Priority score
115.76
Exploit maturity
no public PoC known
CVSS v3
8.8
EPSS score
1.7 %
Moderate — model estimates 1-10% exploitation likelihood.
Published
2026-08-11 17:05 UTC
CWE
CWE-502

Weakness classes (CWE)

  • CWE-502Base

    Deserialization of Untrusted Data

    The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

    cwe.mitre.org →

References & sources

Reanalysis & status changes

Chronological NVD audit events for this CVE — reanalyses, CVSS updates, CPE diffs.

  1. CVE Modified2026-08-11 19:18 UTC· 134c704f-9b21-4f2e-91b3-4a467353bcc0
    • SSVC: {"id":"CVE-2026-70321","role":"CISA Coordinator","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalI…
  2. New CVE Received2026-08-11 17:19 UTC· secure@microsoft.com
    • Affected: Microsoft SharePoint Server Subscription Edition
    • Description: Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
    • CVSS V3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    • CWE: CWE-502

Linked advisories