# CVE-2026-90493: Tonec Internet Download Manager Kernel Driver idmwfp.sys access control

> A local attacker can exploit improper access controls in the IDM kernel driver to read and modify arbitrary registry keys, leading to privilege escalation.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-h6w4-32pj-q5p4

## What is CVE-2026-90493?

CVE-2026-90493 is a critical vulnerability in Tonec Internet Download Manager, published on 13 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A vulnerability was detected in Tonec Internet Download Manager up to 6.42 Build 63 on Windows. The impacted element is an unknown function of the file idmwfp.sys of the component Kernel Driver. The manipulation results in improper access controls. Attacking locally is a requirement. Internet Download Manager for Windows up to and including 6.42 Build 63 installs idmwfp.sys, a Windows kernel driver that exposes the \.\IDMWFP device interface to authenticated local users. The device object is created with an access control descriptor equivalent to D:P(A;;GA;;;AU), granting Authenticated Users generic access to the driver. The driver's IOCTL 0x12C028 handler accepts registry-operation subcommands 0x0C through 0x0F and processes caller-controlled registry paths and values. These handlers do not authenticate the caller, do not enforce the caller's registry permissions, and do not restrict operations to IDM-owned registry namespaces. A low-privileged local authenticated user can therefore read, create, modify, and delete arbitrary registry values under HKLM and HKU through the kernel driver. This includes registry configuration consumed by privileged Windows services and drivers and enables Local Privilege Escalation, high-privilege persistence, unauthorized system configuration disclosure or modification, and compromise of system confidentiality, integrity, and availability. Exploitation requires local access, low privileges, and no user interaction. A public proof of concept is available. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-284 (Improper Access Control), CWE-266 (Incorrect Privilege Assignment)

## Which versions are affected by CVE-2026-90493?


## How do I fix CVE-2026-90493?

No fix has been published for CVE-2026-90493 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90493 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90493 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90493 and fix it if it is affected.

What it is: CVE-2026-90493 is a critical vulnerability in Tonec Internet Download Manager, published on 13 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90493 exists.

Affected product: Tonec Internet Download Manager. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90493/ (Markdown: https://insights.sbomify.com/CVE-2026-90493/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90493
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90493
- OSV: https://osv.dev/vulnerability/CVE-2026-90493

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90493/
Summaries are generated and may contain mistakes; the official description above is the record.