CVE-2026-45659KEV · OVERDUECWE-502

Microsoft SharePoint Remote Code Execution Vulnerability

High · published May 22, 2026

Patch now

Confirmed exploited, and the score agrees

CVSS calls it high at 8.8. It is confirmed in active exploitation. It sits in the 85.9th percentile for exploit probability.

112
days past CISA
deadline
CVSS v3.1
8.8
EPSS
3%
Percentile
85.9
In the wild
Confirmed
What it is

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

The record
Technical detail
CVSS v3.1
8.8 · HIGH
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
CVSS v4.0
Not supplied
EPSS
0.02704 · 85.9th percentile
Weakness
CWE-502 · Deserialization of Untrusted Data
Published
2026-05-22T22:04Z
KEV added
2026-07-01 · due 2026-07-04
EPSS history
Timeline
  • 25 SEP 03:26Z
    EPSS moved 76% → 3%
    epss
  • 01 JUL 00:00Z
    Added to CISA KEV — remediate by Jul 4
    kev
  • 22 MAY 22:04Z
    Microsoft SharePoint Remote Code Execution Vulnerability
    cvelistv5