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NVD / CVE Program· CNA microsoft

CVE-2026-45659: Microsoft SharePoint Remote Code Execution Vulnerability

Noroxi assessment

Priority: Now (action score 89/100)

  • CISA has confirmed exploitation in the wild (Jul 1, 2026); it is known to be used in ransomware campaigns. Remediation deadline for US federal agencies: Jul 4, 2026.
  • Probability of exploitation in the next 30 days: 80.2% (FIRST EPSS); higher than 99.6% of all records.
  • Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Microsoft SharePoint Enterprise Server 2016 16.0.5552.1002; Microsoft SharePoint Server 2019 16.0.10417.20128; Microsoft SharePoint Server Subscription Edition 16.0.19725.20280.

Patch today or shut off access. Upgrade to Microsoft SharePoint Enterprise Server 2016 16.0.5552.1002; Microsoft SharePoint Server 2019 16.0.10417.20128; Microsoft SharePoint Server Subscription Edition 16.0.19725.20280 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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

HighCVSS 8.8 · v3.1KEVWeaponized Fix available
Published
May 22, 2026
Updated
Aug 11, 2026
EPSS
80.2% · 99th percentile

Report tools

JSON

Action score

89

Now

Patch today or shut off access.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
24 / 30 · 80.2%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · microsoft
8.8
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Jul 1, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Jul 4, 2026.

Known to be used in ransomware campaigns.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-45659

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
microsoftsharepoint server

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • microsoft sharepoint serverbefore 16.0.19725.20280
  • microsoft sharepoint server2016
  • microsoft sharepoint server2019

Versions reported by the vendor

Affected version ranges reported by the assigning authority (microsoft). Independent of NVD's CPE analysis and usually ahead of it.

  • Microsoft Microsoft SharePoint Enterprise Server 2016

    • 16.0.0 and later · before 16.0.5552.1002affected

  • Microsoft Microsoft SharePoint Server 2019

    • 16.0.0 and later · before 16.0.10417.20128affected

  • Microsoft Microsoft SharePoint Server Subscription Edition

    • 16.0.0 and later · before 16.0.19725.20280affected

Same product

microsoft: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-53770Microsoft SharePoint Server Remote Code Execution VulnerabilityKEV
    99Now
  • CVE-2023-29357Microsoft SharePoint Server Elevation of Privilege VulnerabilityKEV
    99Now
  • CVE-2025-49704Microsoft SharePoint Remote Code Execution VulnerabilityKEV
    95Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-40365May 12, 2026 · Microsoft SharePoint Server Remote Code Execution Vulnerability
    35Monitor
  • ← EarlierCVE-2026-40368May 12, 2026 · Microsoft SharePoint Server Remote Code Execution Vulnerability
    33Monitor
  • Later →CVE-2026-47294Jun 1, 2026 · Microsoft SharePoint Server Remote Code Execution Vulnerability
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Microsoft SharePoint Enterprise Server 201616.0.5552.1002 · KB5002868Microsoft (MSRC)
Microsoft SharePoint Server 201916.0.10417.20128 · KB5002870Microsoft (MSRC)
Microsoft SharePoint Server Subscription Edition16.0.19725.20280 · KB5002863Microsoft (MSRC)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:12026-05-27

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. First PoC+4 d
  3. CISA KEV+39 d
  4. TodayNov 7, 2026+169 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2025-53770307 days apartMicrosoft SharePoint Server Remote Code Execution VulnerabilityKEV
    99Now
  • CVE-2026-20963129 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV
    78This week
  • CVE-2026-5864453 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV
    74This week
  • CVE-2026-5052253 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV
    70This week
  • CVE-2026-4548418 days apartMicrosoft SharePoint Elevation of Privilege Vulnerability
    45Plan
  • CVE-2026-3311210 days apartMicrosoft SharePoint Server Remote Code Execution Vulnerability
    44Plan

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python
payload = sock.recv(65536)job = pickle.loads(payload)

Fixed

python
payload = sock.recv(65536)if not hmac.compare_digest(sign(payload), header_sig):    raise PermissionError("invalid signature")job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records