Microsoft SharePoint Server Subscription Edition: Access of Resource Using Incompatible Type
CVE-2026-109499 is a high-severity access of resource using incompatible type vulnerability in Microsoft SharePoint Server Subscription Edition from Microsoft, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 16.0.20326.20278 as the first without the flaw, so updating Microsoft SharePoint Server Subscription Edition to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.91% chance of exploitation within 30 days, higher than 61% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Microsoft SharePoint Server Subscription Edition to 16.0.20326.20278 or a later version.
- Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 up to, but not including, 16.0.20326.20278 | 16.0.20326.20278 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (microsoft.com).
Official description
Access of resource using incompatible type ('type confusion') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Access of Resource Using Incompatible Type
The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.
More Access of Resource Using Incompatible Type vulnerabilities (CWE-843)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Other vulnerabilities in Microsoft SharePoint Server Subscription Edition
- 9.0 Critical severity
- 7.3 High severity
- 7.3 High severity
- 8.0 High severity
- 7.3 High severity
- 7.3 High severity
Recent Access of Resource Using Incompatible Type vulnerabilities
- 7.5 High severity
- 8.8 High severity
- 7.0 High severity
- 7.8 High severity
- 8.8 High severity
- 8.8 High severity
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