LIVE · cybersecurity feed
Live wire
ASOS Breach Reveals the Risks in Customer-Facing SaaSUnpatched AhsayCBS flaws exploited to deploy webshells, mine cryptoAI Training Critical as Governance Challenges GrowUS Disrupts Chinese State-Sponsored Hacking ToolsCitrix warns admins to patch new NetScaler RCE flaw immediatelyCisco Patches a Dozen Critical VulnerabilitiesCisco warns of critical flaws allowing Nexus switch takeoverCVE-2026-21589 · Exploitation attempts against critical Atlassian flaw have begun (CVE-2026-21589)Cyber experts call on CISA to create mandatory federal OT rulesGremlin Foresight AI finds system weaknesses and verifies the fixes
cve recordcriticalexploited in the wild3 of 3 cataloguesexploit reported

CVE-2026-50522

Microsoft · SharePoint · Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

Published · Added to CISA KEV
CVSS9.8
Severitycritical
WeaknessCWE-502
EPSS3.0%87.4th percentile
Exploited3 KEV sources
Ransomware useUnknown
Federal fix dueJul 25, 2026

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

patch window

Called exploited 6 days after disclosure.

Measured from the CVE publication date to the earliest of 3 KEV catalogues that list it.

The life of this vulnerability

  1. CVE published
  2. First KEV listing6d
  3. Last KEV listing2d
  4. Last sighting44d

Gaps are compressed to equal steps. The elapsed time is printed under each.

Which catalogues call it exploited

Sources3 of 3
Listings differ by2 d
Strongest claimconfirmed

3 catalogues list it. CIRCL aggregates the others and is shown but not counted.

Public exploitation evidence

21 public reports collected from VulnCheck and CIRCL, first on Jul 20, 2026. Each links to its original source. We have not verified them.

Description

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

Required action (CISA)

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

References

← Back to the CVE Tracker

Our coverage of CVE-2026-50522

CVE-2026-55040critical

Attackers Exploit SharePoint Authentication Bypass After Public PoC Release

Threat actors are actively exploiting a critical Microsoft SharePoint vulnerability, identified as CVE-2026-55040, according to recent reports. This exploitation campaign began shortly after a proof-of-concept (PoC) exploit for the flaw was publicly released. The vulnerability is described as a security feature bypass, enabling unauthenticated attackers to impersonate legitimate users within…

CVE-2008-4128high

July 2026 CVE Landscape

Cybersecurity researchers identified 85 high-impact vulnerabilities in July 2026 that require urgent remediation, marking a 44% increase from the previous month. Of these, 36 were assigned a "Very Critical" risk score by Insikt Group. The vulnerabilities affected products from 61 vendors, with Microsoft accounting for approximately 12% of the total.

CVE-2026-50522critical

Another SharePoint RCE exploited: Patch, then rotate your machine keys (CVE-2026-50522)

Attackers are actively exploiting a critical remote code execution (RCE) vulnerability, CVE-2026-50522, in on-premise Microsoft SharePoint deployments. The primary objective of these attacks is to exfiltrate Internet Information Services (IIS) machine keys, which can grant long-term access to compromised systems.

CVE-2026-50522critical

Public PoC triggers active exploitation of critical SharePoint RCE vulnerability CVE-2026-50522

A critical remote code execution (RCE) vulnerability in Microsoft SharePoint, identified as CVE-2026-50522, is now under active exploitation following the public release of proof-of-concept (PoC) exploit code. The flaw, which carries a CVSS score of 9.8, was addressed by Microsoft in its July 2026 Patch Tuesday updates.

CVE-2026-50522critical

Critical SharePoint RCE flaw exploited to steal machine keys

Threat actors are actively exploiting a critical remote code execution (RCE) vulnerability in Microsoft SharePoint, designated CVE-2026-50522, to compromise on-premise deployments. The flaw, a deserialization-of-untrusted-data issue, allows unauthenticated attackers to execute arbitrary code over a network.