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NVD / CVE Program· CNA microsoft

CVE-2026-20963: Microsoft SharePoint Remote Code Execution Vulnerability

Noroxi assessment

Priority: This week (action score 78/100)

  • CISA has confirmed exploitation in the wild (Mar 18, 2026). Remediation deadline for US federal agencies: Mar 21, 2026.
  • Probability of exploitation in the next 30 days: 29.2% (FIRST EPSS); higher than 98.1% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: Microsoft SharePoint Enterprise Server 2016 16.0.5535.1001; Microsoft SharePoint Server 2019 16.0.10417.20083; Microsoft SharePoint Server Subscription Edition 16.0.19127.20442.

Don’t wait for the next maintenance window. Upgrade to Microsoft SharePoint Enterprise Server 2016 16.0.5535.1001; Microsoft SharePoint Server 2019 16.0.10417.20083; Microsoft SharePoint Server Subscription Edition 16.0.19127.20442 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 unauthorized attacker to execute code over a network.

CriticalCVSS 9.8 · v3.1KEVWeaponized Fix available
Published
Jan 13, 2026
Updated
Jul 30, 2026
EPSS
29.2% · 98th percentile

Report tools

JSON

Action score

78

This week

Don’t wait for the next maintenance window.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
9 / 30 · 29.2%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · microsoft
9.8
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:N/AC:L/PR:N/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 Mar 18, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Mar 21, 2026.

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.

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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 16.0.19127.20442
  • 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 16.0.5535.1001affected

  • Microsoft Microsoft SharePoint Server 2019

    • 16.0.0 and later · before 16.0.10417.20083affected

  • Microsoft Microsoft SharePoint Server Subscription Edition

    • 16.0.0 and later · before 16.0.19127.20442affected

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-2026-20958Jan 13, 2026 · Microsoft SharePoint Information Disclosure Vulnerability
    21Monitor
  • ← EarlierCVE-2026-20959Jan 13, 2026 · Microsoft SharePoint Server Spoofing Vulnerability
    23Monitor
  • Later →CVE-2026-26105Mar 10, 2026 · Microsoft SharePoint Server Spoofing Vulnerability
    37Monitor

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 201616.0.5535.1001 · KB5002828Microsoft (MSRC)
Microsoft SharePoint Server 201916.0.10417.20083 · KB5002825Microsoft (MSRC)
Microsoft SharePoint Server Subscription Edition16.0.19127.20442 · KB5002822Microsoft (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.

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. CISA KEV+63 d
  3. TodayNov 11, 2026+302 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-2025-53770178 days apartMicrosoft SharePoint Server Remote Code Execution VulnerabilityKEV
    99Now
  • CVE-2026-45659129 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV
    89Now
  • CVE-2026-58644182 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV
    74This week
  • CVE-2026-50522182 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV
    70This week
  • CVE-2024-38018490 days apartMicrosoft SharePoint Server Remote Code Execution Vulnerability
    50Plan
  • CVE-2026-45484147 days apartMicrosoft SharePoint Elevation of Privilege Vulnerability
    45Plan

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.
  • No account or password is required.
  • 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
None
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:N/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✗ → ✓

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References

Show all references (1 more)

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

All records