What is CVE-2018-15556?

CVE-2018-15556 is a critical-severity vulnerability in Actiontec Web6000q, classified under Improper Authentication. CVSS score: 9.8/10. Published 2019-06-27.

How severe is CVE-2018-15556?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Auth bypass in Actiontec Web6000q

CVE-2018-15556

The Quantenna WiFi Controller on Telus Actiontec WEB6000Q v1.1.02.22 allows login with root level access with the user "root" and an empty password by using the enabled onboard UART headers.

Vulnerability class: Broken Authentication

Published 2019-06-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.033 (87.9th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 88th percentile — 87.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.033 · newest: 0.033 · change: 0.000

Affected products

Actiontec Web6000q
Actiontec Web6000q Firmware — versions 1.1.02.22

Weakness classification (CWE)

CWE-287 — Improper Authentication

References

seclists.org/fulldisclosure/2019/Jun/1 (mailing-list, Exploit, Mailing List, Third Party Advisory)
packetstormsecurity.com/files/153262/Telus-Actiontec-WEB6000Q-Privilege-Escalat… (Exploit, VDB Entry, Third Party Advisory)

Frequently asked questions

What is CVE-2018-15556?: CVE-2018-15556 is a critical-severity vulnerability in Actiontec Web6000q, classified under Improper Authentication. CVSS score: 9.8/10. Published 2019-06-27.
How severe is CVE-2018-15556?: Critical severity. CVSS v3 base score is 9.8 out of 10.