Microsoft Dynamics 365 (on-premises) version 9.1: Improper Handling of Exceptional Conditions
CVE-2026-40371 is a high-severity improper handling of exceptional conditions vulnerability in Microsoft Dynamics 365 (on-premises) version 9.1 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 9.1.0045.0011 as the first without the flaw, so updating Microsoft Dynamics 365 (on-premises) version 9.1 to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Microsoft Dynamics 365 (on-premises) version 9.1 to 9.1.0045.0011 or a later version.
- Update Dynamics 365 to 9.1.45.11 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 Dynamics 365 (on-premises) version 9.1 | 9.0 up to, but not including, 9.1.0045.0011 | 9.1.0045.0011 |
| Microsoft | Dynamics 365 | 9.1 up to, but not including, 9.1.45.11 | 9.1.45.11 |
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
Improper handling of insufficient permissions or privileges in Microsoft Dynamics 365 (on-premises) allows an authorized attacker to elevate privileges over a network.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Exceptional Conditions
The product does not handle or incorrectly handles an exceptional condition.
More Improper Handling of Exceptional Conditions vulnerabilities (CWE-755)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Microsoft Dynamics 365 (on-premises) version 9.1
- 9.9 Critical severity
- 9.1 Critical severity
Recent Improper Handling of Exceptional Conditions vulnerabilities
- 8.7 High severity
- 7.5 High severity
- 7.5 High severity
- 7.3 High severity
- 7.5 High severity
- 7.5 High severity
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