Search: “Microsoft SharePoint Server Subscription Edition”

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CVE-2026-50522 is an unauthenticated .NET deserialization RCE in SharePoint Server Subscription, 2019, and 2016; Microsoft patched it July 14, 2026.

CVE-2026-50522 (CWE-502) lets unauthenticated attackers send crafted serialized .NET payloads to network-accessible SharePoint endpoints, triggering gadget-chain deserialization and remote code execution under the privileged SharePoint service account. It affects SharePoint Server Subscription Edition, SharePoint Server 2019, and SharePoint Server 2016 Enterprise; Microsoft published the advisory on July 14, 2026. The EPSS score is 20.346%, but no public PoC exists and the flaw is not in CISA's KEV catalog at publication. Mitigations include applying Microsoft updates, rotating SharePoint machine keys, enabling AMSI, and restricting internet exposure.

Web discovery (articles for new exploits & KEV entries)Sep 7, 19:42 UTC · 8d agoVulnerability 3 sources CVE-2026-505221

CISA warns of active exploitation of Microsoft SharePoint vulnerability (CVE-2026-20963)

Help Net SecurityMar 19, 00:00 UTC · Mar 19, 2026Vulnerability in the wildCVE-2026-20963

Microsoft pins on-prem SharePoint attacks on Chinese threat actors

Help Net SecurityJul 24, 15:45 UTC · Jul 24, 2025Threat actor in the wildCVE-2025-49706 CVE-2025-49704 CVE-2025-53770+1 CVEs

Microsoft security advisory – September 2026 monthly rollup (AV26-896) – Update 1

Canada's Cyber Centre relays Microsoft's September 2026 rollup; CISA added exploited zero-days CVE-2026-85880 and CVE-2026-81963 to KEV.

Advisory AV26-896 from the Canadian Centre for Cyber Security summarizes Microsoft's September 2026 monthly security rollup, listing affected products across Windows, Office, .NET, Azure, Exchange and SQL Server. It notes Microsoft confirmed CVE-2026-81963 and CVE-2026-85880 have been exploited. On September 8, 2026, CISA added both CVEs to its Known Exploited Vulnerabilities catalog, and administrators are urged to apply the updates.

Canadian Centre for Cyber SecuritySep 8, 19:03 UTC · 7d agoAdvisory in the wildCVE-2026-81963 CVE-2026-858801

Researchers Disclose AI-Assisted SharePoint Exploit Chain Reaching Unauthenticated RCE

Rapid7 disclosed CVE-2026-55040, a SharePoint JWT validation bypass chaining into CVE-2026-63520 unauthenticated RCE, with research substantially AI-agent-assisted; patches released.

Rapid7 disclosed CVE-2026-55040 (CVSS 9.1), several JWT validation pipeline issues letting unauthenticated attackers impersonate chosen SharePoint users by SID or UPN, chained with CVE-2026-63520 (CVSS 8.1), an unsafe .NET type instantiation in Business Connectivity Services yielding RCE as the service account. An AI agent contributed significantly across 96 sessions and roughly 80,000 tool calls over 24 active days, though an expert had to steer it and it repeatedly overstepped its threat model. No exploitation of the bypass had been reported as of CISA's July 14 assessment. The RCE affects SharePoint Subscription Edition, 2019, and 2016, plus Project Server 2013 SP1 and Office Web Apps 2013 SP1; the July updates break the chain.

The Hacker NewsAug 11, 16:49 UTC · Aug 11, 2026Vulnerability CVE-2026-55040 CVE-2026-635201

SharePoint RCE CVE-2026-45659 Added to CISA KEV After Active Exploitation

CISA adds actively exploited SharePoint RCE CVE-2026-45659 (CVSS 8.8) to KEV; an August 11 update confirms ransomware groups are exploiting the flaw.

CVE-2026-45659 is a deserialization of untrusted data RCE in Microsoft SharePoint Server affecting Subscription Edition, 2019, and 2016, patched by Microsoft in May 2026. An authenticated attacker with at least Site Member permissions can execute code remotely over the network. CISA added the flaw to its KEV catalog on July 2 with a July 4 deadline for federal agencies, and on August 11 confirmed ransomware groups are exploiting it. Microsoft separately described Storm-2603 (Warlock ransomware) and an unrelated actor co-existing in one network, with initial access likely via the Gladinet Triofox flaw CVE-2025-11371 (CVSS 9.1).

The Hacker NewsAug 12, 13:46 UTC · Aug 12, 2026Exploit / PoC in the wildCVE-2026-45659 CVE-2025-113711

Microsoft linked attacks on SharePoint flaws to China

Security AffairsJul 23, 06:20 UTC · Jul 23, 2025Ransomware CVE-2025-53770

U.S. CISA adds a Microsoft SharePoint Server flaw to its Known Exploited Vulnerabilities catalog

Security AffairsJul 2, 15:57 UTC · Jul 2, 2026Exploit / PoC in the wildCVE-2026-45659 CVE-2026-322011

SharePoint CVE-2026-55040 Comes Under Attack Following Public Exploit

Attackers are actively exploiting critical SharePoint authentication bypass CVE-2026-55040 (CVSS 9.1) days after Rapid7 released a public PoC.

CVE-2026-55040 is a critical authentication bypass (CVSS 9.1) in SharePoint Server Subscription Edition that lets unauthenticated attackers forge JWT tokens and impersonate any user, including administrators. Microsoft patched it in July 2026 Patch Tuesday, but Rapid7 published a technical write-up and Python PoC on GitHub on August 12, and Defused quickly observed attackers running the PoC against SharePoint honeypots. KEVIntel recorded 12 exploitation attempts since July 19, with eight occurring on August 12-13 from IP addresses in Hong Kong, Japan, the Netherlands, Taiwan and the U.S. Admin-level SharePoint access exposes documents and data modification and can serve as a foothold into broader Microsoft 365 infrastructure; unpatched instances should apply the July update immediately.

Security AffairsAug 13, 08:36 UTC · Aug 13, 2026Exploit / PoC in the wildCVE-2026-55040

Rapid7 Analysis: Microsoft SharePoint JWT Token Authentication Bypass (CVE-2026-55040)

Rapid7's analysis of SharePoint auth bypass CVE-2026-55040 includes a PoC for unauthenticated admin-level operations.

Rapid7 and Microsoft disclosed CVE-2026-55040, an authentication bypass in Microsoft SharePoint, on July 14, 2026. The flaw stems from multiple issues in SharePoint's JWT token validation pipeline, allowing a remote unauthenticated attacker to bypass authentication and perform operations as a site user or administrator. Rapid7 has now published a technical analysis and a proof-of-concept script, based on SharePoint Server Subscription Edition.

Rapid7 BlogAug 11, 13:00 UTC · Aug 11, 2026Vulnerability CVE-2026-550401

Risky Bulletin: Slovakia finds Russian backdoor in traffic speed cameras

Slovakia's NBU found an SMS-triggered backdoor in Russian-made NERO R-ONE traffic cameras, pausing a 279-unit deployment.

Slovakia's national security service NBU issued an alert against NERO R-ONE high-speed traffic cameras after finding a backdoor that grants shell and network access via SMS from hardcoded Russian phone numbers. The cameras are a rebranded version of the Russian CORDON PRO.M model by St. Petersburg firm Semicon, purchased via a Cyprus shell company under a €30 million EU-funded project. The report also found SecureBoot disabled, vulnerable web management, and unauthenticated live streams; the Interior Ministry paused deployment of 279 cameras pending independent assessment.

Risky Business NewsAug 19, 04:52 UTC · 28d agoThreat actor in the wild1

U.S. CISA adds Apple macOS, Microsoft SharePoint, Broadcom VMware vCenter, and Microsoft IKE flaws to its Known Exploited Vulnerabilities catalog

CISA adds actively exploited flaws in Microsoft IKE, SharePoint, VMware vCenter, and macOS Screen Sharing to KEV catalog, due August 21.

CISA added four vulnerabilities to its Known Exploited Vulnerabilities catalog: CVE-2026-33824 (Windows IKE remote code execution, CVSS 9.8), CVE-2026-55040 (SharePoint JWT authentication bypass, CVSS 9.1), CVE-2026-59310 (VMware vCenter Syslog path traversal, CVSS 9.8), and CVE-2026-65400 (macOS Screen Sharing improper authentication). The SharePoint flaw combines four weaknesses including alg:none JWT forging to impersonate any user, with Defused researchers observing attackers using Rapid7's PoC against honeypots. The Dutch NCSC confirmed active exploitation of the macOS Screen Sharing flaw on August 15, 2026. Federal agencies must patch by August 21, 2026.

Security AffairsAug 19, 07:19 UTC · 28d agoExploit / PoC in the wildCVE-2026-33824 CVE-2026-55040 CVE-2026-59310+1 CVEs

September 2026 Microsoft Patch Tuesday, (Tue, Sep 8th)

Microsoft's September 2026 Patch Tuesday fixes a record 973 vulnerabilities, including 113 critical and two Windows privilege-escalation flaws already exploited in the wild.

Microsoft patched 973 vulnerabilities this month, its largest Patch Tuesday ever and far above the previous record of 664 set in July 2026, with 113 rated critical. Two Important elevation-of-privilege flaws (CVSS 7.8) are confirmed exploited in the wild: CVE-2026-81963 in the Windows Update Stack (improper link resolution, affects Windows 11 and Server 2025) and CVE-2026-85880 in Windows ALPC (heap-based buffer overflow allowing sandbox escape to SYSTEM, affects Windows 10 and Server 2012-2022). Critical unauthenticated RCEs (CVSS 9.8) were also fixed in Skype for Business Server (CVE-2026-66302), Windows Message Queuing (CVE-2026-69579), and Windows RRAS (CVE-2026-69590). SANS urges prioritizing the two exploited EoP fixes, then patching exposed MSMQ, RRAS, and Skype for Business deployments.

SANS Internet Storm CenterSep 8, 19:20 UTC · 7d agoVulnerability in the wildCVE-2026-81963 CVE-2026-85880 CVE-2026-66302+5 CVEs1