CVE-2026-55040

critical

Description

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

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040

https://www.securityweek.com/fresh-sharepoint-vulnerability-exploited-soon-after-disclosure/

https://www.theregister.com/security/2026/07/15/cisa-sounds-alarm-over-trio-of-exploited-sharepoint-flaws/5271814

https://www.securityweek.com/cisa-urges-immediate-patching-of-exploited-sharepoint-vulnerabilities/

https://www.bleepingcomputer.com/news/security/cisa-warns-admins-to-patch-actively-exploited-sharepoint-flaws/

https://therecord.media/microsoft-vulnerabilities-patch-tuesday-release

https://thehackernews.com/2026/07/researcher-drops-new-windows-zero-day.html

https://www.cisa.gov/news-events/alerts/2026/07/14/cisa-urges-sharepoint-hardening-after-new-exploitations

https://thehackernews.com/2026/07/microsoft-patches-record-622-flaws.html

https://www.tenable.com/blog/cve-2026-32201-cve-2026-45659-cve-2026-56164-faq-sharepoint-server-exploitation

Details

Source: Mitre, NVD

Published: 2026-07-14

Updated: 2026-07-15

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 9.1

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

Severity: Critical

EPSS

EPSS: 0.00682