Microsoft SharePoint Server: Information disclosure via authorization bypass
Summary
Microsoft SharePoint Server Subscription Edition (on-premises) builds from 16.0.0 before 16.0.20326.20278 contain an authorization bypass through a user-controlled key (CWE-639). An authenticated attacker with a low-privilege account can disclose information over the network without user interaction. The impact is limited to confidentiality, and the sources do not specify which data can be exposed.
Affected
- Microsoft SharePoint Server Subscription Edition (x64): 16.0.0 before 16.0.20326.20278
- Other SharePoint editions: not listed for this CVE in the sources reviewed; verify on the MSRC page.
Fixed in
- Build 16.0.20326.20278 or later, released with Microsoft's November 2026 Patch Tuesday updates.
- KB article number: Unknown.
Workaround
Unknown. No workaround was found in the sources reviewed; the patch is the only documented remediation so far.
Exploitation
- Exploited in the wild: no evidence found; not listed in CISA KEV according to a third-party tracker.
- CISA SSVC: Exploitation none, Automatable no, technical impact partial.
- Rapid7: Exploitation Less Likely, not publicly disclosed.
- Public proof of concept: none found.
Our recommendation
- Identify on-premises SharePoint Subscription Edition servers and their build numbers.
- Install the November 2026 cumulative update so the build is at least 16.0.20326.20278.
- Check whether SharePoint servers are reachable from the internet and restrict public exposure where feasible.
- Review low-privilege accounts and remove unused ones, as a valid account is required for exploitation.
- Monitor MSRC and NVD for completed analysis, CISA KEV listing or proof-of-concept publication.
Information from Microsoft (Patch Tuesday November 2026)
- Severity (Microsoft)
- Important
- Impact
- Information disclosure – Microsoft Office SharePoint
- Status on Patch Tuesday
- Neither exploited nor publicly disclosed
- Exploitability assessment
- Exploitation less likely
- Product family
- Microsoft Office
- Updates (KB)
- KB5002945
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Microsoft Security Response Center: CVE-2026-110057 msrc.microsoft.com
- CVE Record CVE-2026-110057 www.cve.org
- Strix: CVE-2026-110057 www.strix.ai
- Cybersecurity News: Microsoft November 2026 Patch Tuesday cybersecuritynews.com
- Rapid7: Patch Tuesday November 2026 www.rapid7.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 12:33.
Original description (NVD)
Authorization bypass through user-controlled key in Microsoft Office SharePoint allows an authorized attacker to disclose information over a network.
NVD references (1)
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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