CRITICAL🚩 CISA KEV⚡ EXPLOIT✓ PATCH🇵🇱 Wersja polska

CVE-2026-55040

CVSS 9.1v3.1pub. 2026-07-14upd. 2026-08-18

Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.

CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
  • Microsoft SharePoint Server

    APP
    Microsoft
    20162019< 16.0.19725.20434

CISA KEV — detailsi

Vendori
Microsoft
Producti
SharePoint
Added to KEVi
August 18, 2026
Remediation deadline (US Federal)i
August 21, 2026(overdue)
Required action (CISA)i

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.

CISA descriptioni

Microsoft SharePoint contains a weak authentication vulnerability which allows an unauthorized attacker to bypass a security feature over a network.

🔴
IMMEDIATE ACTION
Actively exploited in the wild (CISA KEV). Patch immediately.
CISA DEADLINE: 21 sierpnia 2026
CWE
References

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