Microsoft SharePoint Server Spoofing Vulnerability
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to perform spoofing over a network.
- Published
- Jun 9, 2026
- Updated
- Sep 24, 2026
- EPSS
- 1.1% · 64th percentile
- CWE
- CWE-502
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Report tools
Action score
21
Monitor
Low priority for now.
- CVSS
- 21 / 40 · 5.4 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 1.1%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.4
- CNA · microsoft
- 5.4
- agree
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N/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.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| microsoft | sharepoint server | cpe:2.3:a:microsoft:sharepoint_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 16.0.19725.20384
- 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 16.0.5556.1005affected
Microsoft Microsoft SharePoint Server 2019
- 16.0.0 and later · before 16.0.10417.20153affected
Microsoft Microsoft SharePoint Server Subscription Edition
- 16.0.0 and later · before 16.0.19725.20384affected
Same product
microsoft: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-53770Microsoft SharePoint Server Remote Code Execution VulnerabilityKEV99Now
- CVE-2023-29357Microsoft SharePoint Server Elevation of Privilege VulnerabilityKEV99Now
- CVE-2025-49704Microsoft SharePoint Remote Code Execution VulnerabilityKEV95Now
- CVE-2026-20963Microsoft SharePoint Remote Code Execution VulnerabilityKEV78This week
- CVE-2026-58644Microsoft SharePoint Remote Code Execution VulnerabilityKEV74This week
- CVE-2024-38094Microsoft SharePoint Remote Code Execution VulnerabilityKEV73This week
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
No fix version is recorded for this entry. Check the references for vendor advisories.
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
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.
No dated events beyond publication.
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 researchersFinders, 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-2025-53770325 days apartMicrosoft SharePoint Server Remote Code Execution VulnerabilityKEV99Now
- CVE-2026-20963147 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV78This week
- CVE-2026-5864435 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV74This week
- CVE-2026-5052235 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV70This week
- CVE-2026-4565918 days apartMicrosoft SharePoint Remote Code Execution VulnerabilityKEV66This week
- CVE-2025-54897273 days apartMicrosoft SharePoint Remote Code Execution Vulnerability41Plan
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
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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.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- low · data or configuration can be modified
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- Low
- Availability impact
- None
Weakness class (CWE)
CWE-502 · Deserialization of Untrusted DataCVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
nvd-primary
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 classA representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.
Vulnerable
payload = sock.recv(65536)job = pickle.loads(payload)Fixed
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.
Attack patterns (CAPEC)
ATT&CK techniques
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Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.