CVE-2026-58644

critical

Description

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

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58644

https://www.securityweek.com/fourth-sharepoint-vulnerability-exploited-in-past-months-wave-of-attacks/

https://www.helpnetsecurity.com/2026/07/22/sharepoint-cve-2026-50522-exploited/

https://thehackernews.com/2026/07/critical-sharepoint-rce-cve-2026-50522.html

https://securityaffairs.com/195569/security/u-s-cisa-adds-fortinet-fortisandbox-and-microsoft-sharepoint-flaws-to-its-known-exploited-vulnerabilities-catalog.html

https://www.theregister.com/security/2026/07/17/attackers-target-critical-fortisandbox-flaws-as-cisa-issues-patch-order/5274287

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

https://thehackernews.com/2026/07/cisa-adds-exploited-sharepoint-rce-zero.html

https://www.cisa.gov/news-events/alerts/2026/07/16/cisa-adds-three-known-exploited-vulnerabilities-catalog

https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-58644

https://securityaffairs.com/195889/security/u-s-cisa-adds-microsoft-sharepoint-and-check-point-smartconsole-flaws-to-its-known-exploited-vulnerabilities-catalog.html

https://securityaffairs.com/195760/security/public-poc-triggers-active-exploitation-of-critical-sharepoint-rce-vulnerability-cve-2026-50522.html

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://www.darkreading.com/vulnerabilities-threats/records-broken-patch-tuesday-raises-triage-stakes

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

https://securityaffairs.com/195347/security/patch-tuesday-security-updates-for-july-2026-the-largest-update-ever-621-cves-in-one-month.html

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

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-58644

Details

Source: Mitre, NVD

Published: 2026-07-14

Updated: 2026-07-17

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 10

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

Severity: Critical

CVSS v3

Base Score: 9.8

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

Severity: Critical

EPSS

EPSS: 0.01324

Vulnerability Watch

Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.

Vulnerability of Interest