Important CVSS 8.8 EPSS 0.02108 2026-05 archive

Executive Summary

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

Overview

8.8
CVSS HIGH
Important
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
Category Remote Code Execution
Released May 12 2026
Last Updated May 12 2026
Publicly Disclosed No
CISA KEV Not Listed
Known Exploits None Known
EPSS Score 0.02108 — 0.7936 percentile
NVD CVSS 8.8 HIGH — matches MSRC

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Network
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
Low
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.7

EPSS Score

0.02108
probability of exploitation in the next 30 days
0.7936 percentile - updated 2026-06-21
View on FIRST.org

Affected Products

3 affected products
Product KB Article Severity Impact Restart Required
Microsoft SharePoint Enterprise Server 2016 5002868 (Security Update) Important Remote Code Execution Maybe
Microsoft SharePoint Server 2019 5002870 (Security Update) Important Remote Code Execution Maybe
Microsoft SharePoint Server Subscription Edition 5002863 (Security Update) Important Remote Code Execution Maybe

Patches

3 patches
Article Type Restart
5002868 Security Update Maybe
5002870 Security Update Maybe
5002863 Security Update Maybe

Known Exploits

Acknowledgments