Telerik UI for ASP.NET MVC: Concurrent Execution using Shared Resource with Improper Synchronization
CVE-2026-106137 is a high-severity concurrent execution using shared resource with improper synchronization vulnerability in Telerik UI for ASP.NET MVC from Progress Software, with a CVSS 3.1 base score of 8.6 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 2026.3.1015 as the first without the flaw, so updating Telerik UI for ASP.NET MVC to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.49% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Telerik UI for ASP.NET MVC to 2026.3.1015 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Progress Software | Telerik UI for ASP.NET MVC | 2012.2.710 up to, but not including, 2026.3.1015 | 2026.3.1015 |
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
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (progress.com).
Official description
In affected versions of Progress® Telerik® UI for ASP.NET MVC `2012.2.710` through `2026.3.811`, ClassFactory updates a shared class dictionary without exclusive write protection and emits non-collectible dynamic assemblies that remain loaded for the AppDomain's lifetime. The dictionary lookup and insertion are not atomic, and case variations in aggregate descriptors can produce distinct retained types even though member resolution is case-insensitive. An unauthenticated remote attacker can exploit this if the application exposes an aggregation endpoint that is reachable without authentication, by submitting concurrent or repeated crafted requests. These requests may corrupt dictionary state or increase CPU and memory use, potentially degrading availability. The issue is fixed in version `2026.3.1015`.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Concurrent Execution using Shared Resource with Improper Synchronization
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
How developers prevent this class of flaw
- In languages that support it, use synchronization primitives. Only wrap these around critical code to minimize the impact on performance.
- Use thread-safe capabilities such as the data access abstraction in Spring.
- Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring. Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Other references
Other vulnerabilities in Telerik UI for ASP.NET MVC
- 8.6 High severity
Recent Concurrent Execution using Shared Resource with Improper Synchronization vulnerabilities
- 8.1 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
- 7.0 High severity
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