CVE-2026-45659

high

Description

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

From the Tenable Blog

SharePoint CVEs FAQ: CVE-2026-56164, CVE-2026-32201, CVE-2026-45659 | Tenable®

SharePoint CVEs FAQ: CVE-2026-56164, CVE-2026-32201, CVE-2026-45659 | Tenable®

Published: 2026-07-16

CISA confirmed exploitation of three SharePoint Server CVEs. Patches, AMSI IoCs, and details on CVE-2026-32201, CVE-2026-45659, CVE-2026-56164.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45659

https://www.bleepingcomputer.com/news/security/hackers-target-microsoft-sharepoint-rce-chain-with-poc-exploit/

https://www.bleepingcomputer.com/news/security/cisa-windows-task-host-flaw-now-exploited-by-ransomware-gangs/

https://thehackernews.com/2026/08/attackers-exploit-sharepoint.html

https://www.securityweek.com/sharepoint-vulnerability-exploited-shortly-after-poc-release/

https://www.bleepingcomputer.com/news/microsoft/hackers-leverage-new-microsoft-sharepoint-exploit-in-attacks/

https://www.bleepingcomputer.com/news/security/cisa-microsoft-sharepoint-flaw-now-exploited-in-ransomware-attacks/

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

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

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

https://thehackernews.com/2026/07/cisa-adds-exploited-sharepoint-rce-zero.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://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://www.theregister.com/security/2026/07/02/microsoft-said-exploitation-was-less-likely-but-cisa-just-added-sharepoint-rce-to-kev-list/5265886

https://www.securityweek.com/cisa-warns-of-actively-exploited-microsoft-sharepoint-vulnerability/

https://www.bleepingcomputer.com/news/security/cisa-microsoft-sharepoint-rce-flaw-now-actively-exploited/

https://thehackernews.com/2026/07/sharepoint-rce-cve-2026-45659-added-to.html

https://securityaffairs.com/194654/security/u-s-cisa-adds-a-microsoft-sharepoint-server-flaw-to-its-known-exploited-vulnerabilities-catalog.html

https://www.cisa.gov/news-events/alerts/2026/07/01/cisa-adds-one-known-exploited-vulnerability-catalog

https://securityaffairs.com/192730/security/microsoft-sharepoint-has-a-new-rce-flaw-if-you-havent-patched-yet-go-do-that.html

https://www.helpnetsecurity.com/2026/05/26/sharepoint-vulnerability-cve-2026-45659/

https://www.darkreading.com/vulnerabilities-threats/microsoft-issues-sharepoint-patch

https://thehackernews.com/2026/05/microsoft-patches-sharepoint-rce-flaw.html

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

https://github.com/WismanSec/sharepoint-2026-poc

https://github.com/cyberupdates365/ai-cyber-threats-and-cve-mitigation-tracker-2026

https://github.com/ChPratik/Threat_intelligence_Portfolio

https://github.com/wilsonvs/Cybersecurity-Research

https://github.com/eason4kim-rocket/purify-feeds-mcp

https://github.com/Byungju/cve-research-lab

https://github.com/jenniferreire26/CVE-2026-45659

https://github.com/daniel30padd/CVE-2026-45659

https://github.com/mistbarbarianspot/CVE-2026-45659-SharePoint-RCE

https://github.com/HORKimhab/CVE-2026-45659

https://github.com/cataam-security/cataam

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-45659

Details

Source: Mitre, NVD

Published: 2026-05-22

Updated: 2026-07-23

Known Exploited Vulnerability (KEV)

Risk Information

CVSS v2

Base Score: 9

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

Severity: High

CVSS v3

Base Score: 8.8

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

Severity: High

EPSS

EPSS: 0.76075

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