CRITICALCVSS 9.8Actively exploited · CISA KEV since 2025-07-20Vulnerability

CVE-2025-53770

Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-53771. CVE-2025-53770 is a patch bypass for CVE-2025-49704, and the updates for CVE-2025-53770 include more robust protection than those for CVE-2025-49704.

Properties

Euvd product
Microsoft SharePoint Server 2019, Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server Subscription Edition
Vulnerability name
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
First seen
2026-08-04T03:55:52+00:00
Cvss score
9.8
Epss score
0.99999
Last seen
2026-10-19T12:00:27+00:00
Due date
2025-07-21
Euvd assigner
microsoft
Retrieved at
2026-10-21T01:24:48+00:00
Exploited euvd since
2025-07-20T00:00:00+00:00
Src batch id
epss_history-20261020T103617Z-728ddd
Source url
https://epss.empiricalsecurity.com/epss_scores-2026-10-19.csv.gz
Date added
2025-07-20
Euvd base score version
3.1
Score
9.8
Fetched at
2026-10-20T10:36:20+00:00
Euvd vendor
Microsoft
Cvss vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
In Signal since
initial import (Sep 2026)
Euvd base score
9.8

Related Entities (14)

MENTIONED_IN (7)

→[Campaign]Unnamed campaign (ID 6977…)
→[Campaign]ClingSTUN Turns Vulnerable Edge Devices Into Attacker Infrastructure
→[Campaign]Lunex Uses BYOVD to Disable Security Monitoring and Deploy Persistent Stealer
→[Campaign]Warlock Ransomware Attackers Hit Water and Telecom Operators
→[Campaign]NightLedger Backdoor Deployed in Espionage Campaign Targeting the Middle East and Africa
→[Campaign]ClickFix-Themed Campaign Deploys Starland RAT and WLDR Framework
→[Campaign]Chrome Extensions: Are you getting more than you bargained for?

AFFECTS_PRODUCT (3)

→[Product]cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*
→[Product]cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*
→[Product]cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*

INVOLVES (2)

←[EmergentSignal]velocity_anomaly
←[Signal]kev_added · 2025-07-20

DESCRIBES (1)

←[KEVEntry]Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

HAS_WEAKNESS (1)

→[Weakness]Deserialization of Untrusted Data

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CVE-2025-53770 (CVSS 9.8) — Ninja Signal Threat Intelligence | Ninja Signal