CVE
ClassFactory Race Condition and Retained Assembly Memory in Telerik UI for ASP.NET MVC
- Exploited
- No known exploitation
- Fix
- Fixed in 2026.3.1015
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 2026.3.1015.
- Last modified
- Whether it needs action now or is a reference record, by fixed rules, with why. Last checked is when cve.now last re-read it.What do these mean? →
- Reference
- Last checked
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 26/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Progress Telerik UI for ASP.NET MVC has a flaw in its ClassFactory component, where unsynchronized updates to a shared class dictionary and retained dynamic assemblies can be triggered. An unauthenticated attacker on the network can exploit this by sending concurrent or repeated crafted requests to an aggregation endpoint that is reachable without logging in, which may corrupt internal state or consume enough CPU and memory to degrade availability. This only applies if the application exposes such an endpoint.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original 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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure17/25No login or user action needed per the CVSS vector, reachable over the network without a login · Unknown: No advisory context yet
- Reach?/20Unknown. No tracked technology or package matched
- Severity8.6/10CVSS 8.6
- No patch0/5No signal
What would change the score
- Would score about 71 if added to CISA KEV
- Would score about 66 if CISA's SSVC rates exploitation active
- Would score about 31 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 2026.3.1015.
Check your systems with an agent
Paste this into a coding or ops agent. It checks your systems read-only and reports a table per asset.
Check whether my systems are affected by CVE-2026-106137 (ClassFactory Race Condition and Retained Assembly Memory in Telerik UI for ASP.NET MVC), using the cve.now data below.
Rules: work read-only. Do not run exploit code, proof-of-concept scripts or scanners that send attack payloads, and do not change any configuration, package, image or deployment. Report findings only.
What cve.now has for CVE-2026-106137 (entry last updated 2026-11-11):
Affected:
- Progress Software Telerik UI for ASP.NET MVC: from 2012.2.710, fixed in 2026.3.1015
Fixed versions: 2026.3.1015.
Setup: unknown whether the bug needs a non-default feature or setting. Check the advisory.
CISA KEV: CVE-2026-106137 is not listed as of cve.now's last read.
This KEV status is for CVE-2026-106137 only. If you also check another CVE, look up its own KEV status; never assume it from this one.
How to check:
- Installed software: check what is actually running, not what a repo declares. Read the version from each host, container image and Kubernetes node (the binary's version output, the OS package database, image layers), and check whether the conditions above hold there. Distribution packages may carry a backported fix under an older version number; confirm against the distribution's own advisory.
Verify against the linked advisories before concluding, and cite the date you read each one:
- https://www.telerik.com/aspnet-mvc/documentation/knowledge-base/kb-security-class-factory-cve-2026-106137
Do not conclude an asset is unaffected unless you checked it and the evidence covers both its version and the conditions above. If you could not check something, mark it unknown and say what is missing.
Report a table with one row per asset and these columns: Asset | Version or build | Status (affected, fixed, not applicable, unknown) | Compensating controls | Exposure (internet-facing, internal, none) | Evidence | Next action.
Entry: https://cve.now/CVE-2026-106137
For follow-up questions, use the cve.now MCP server at https://mcp.cve.now/mcp (no authentication), for example execute with name cve.get and arguments {"id": "CVE-2026-106137"}.Timeline
- CVE published
- First seen by cve.now
Affected versions
- Progress Software Telerik UI for ASP.NET MVC
From 2012.2.710 · fixed in 2026.3.1015
Evidence 3
Vendor advisory · 1
Establishes: Affected and fixed versions.
- Advisory
CVE record · 2
Establishes: The identifier and description.
- Record
- Record
Corrections
None so far.
Something wrong on this page? Report an error. Every fix is listed here.
Questions about CVE-2026-106137
Is CVE-2026-106137 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-106137?
Telerik UI for ASP.NET MVC: from 2012.2.710 before 2026.3.1015.Source: cve.now feed data
How do I fix CVE-2026-106137?
Upgrade to a fixed version: 2026.3.1015.Source: cve.now feed data