# CVE-2026-120345: WAVLINK WN551X3-A OS command injection in DNS resolution handler

Source: https://junglewise.ai/threats/cve-2026-120345-a-vulnerability-was-found-in-wavlink-wn551x3-a-m51x3-v251020-wo  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-02. Updated: 2026-11-02  
License: CC BY 4.0 with a link back

CVE-2026-120345 · Severity: critical · CVSS 10 · Published 2026-11-02

WAVLINK WN551X3-A is a Wi-Fi router that provides DNS resolution functionality through its web interface. A flaw in the DNS resolution handler allows an attacker to inject arbitrary shell commands that execute with root privileges, potentially giving complete control over the router and any connected network. The vulnerability can be exploited remotely via local network access or through SSRF attacks without authentication.

Vendors: [Wavlink](https://junglewise.ai/threats/vendors/wavlink).

## Quick answers

**Is CVE-2026-120345 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-120345 being exploited in the wild.

**How severe is CVE-2026-120345?** Critical severity, with a CVSS score of 10, published 2 November 2026.

**Which products and versions are affected?** Wavlink WN551X3-A M51X3_V251020-WO-182e965.

**Is there a fix for CVE-2026-120345?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-120345 attacked?** It is attacked over the network or from the adjacent network, in a network appliance.

**Am I affected by CVE-2026-120345?** Check whether you run Wavlink WN551X3-A at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The /bin/ioos daemon (WAVLINK's CSP web back-end) contains an OS command injection vulnerability in the dns_resolution handler (sub_41a430) where user-controlled "data" parameter is embedded unquoted into a shell command passed to popen(). The input validator only rejects semicolons but allows newline characters (\n), enabling bypass by injecting newline-separated commands (e.g., data=8.8.8.8\nid). Exploitation requires either loopback/SSRF access to port 81 or a valid session token; the localhost IP-FROM header bypasses authentication, resulting in unauthenticated remote code execution as root.

## Affected products

- WAVLINK WN551X3-A M51X3_V251020-WO-182e965

## Timeline

- 2026-11-02: disclosed

## References

- [https://github.com/senxitoyshuyi-ui/HACKALL/blob/main/WAVLINK_WN551X3-A%20Router/WAVLINK_WN551X3-A_dns_resolution_command_injection.md](https://github.com/senxitoyshuyi-ui/HACKALL/blob/main/WAVLINK_WN551X3-A%20Router/WAVLINK_WN551X3-A_dns_resolution_command_injection.md)
- [https://vuldb.com/cve/CVE-2026-120345](https://vuldb.com/cve/CVE-2026-120345)

## Related threats

- [WAVLINK WN551X3-A OS command injection in WireGuard CLI](https://junglewise.ai/threats/cve-2026-120344-a-vulnerability-has-been-found-in-wavlink-wn551x3-a-m51x3)