What is CVE-2025-51451?

CVE-2025-51451 is a critical-severity vulnerability in Totolink Ex1200t, classified under Improper Authentication. CVSS score: 9.8/10. Published 2025-08-13.

How severe is CVE-2025-51451?

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

Is CVE-2025-51451 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Auth bypass in Totolink Ex1200t

CVE-2025-51451

In TOTOLINK EX1200T firmware 4.1.2cu.5215, an attacker can bypass login by sending a specific request through formLoginAuth.htm.

Vulnerability class: Broken Authentication

Published 2025-08-13 · last modified 2026-07-05.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (29.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 30th percentile — 29.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Totolink Ex1200t
Totolink Ex1200t Firmware — versions 4.1.2cu.5215

Weakness classification (CWE)

CWE-287 — Improper Authentication

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

www.totolink.net/home/menu/detail/menu_listtpl/download/id/204/ids/36.html (Product)
n200re.com (Broken Link)
gist.github.com/lin-3-start/e42344d5caea881e5429fdd40fad1fd8 (Third Party Advisory)

Frequently asked questions

What is CVE-2025-51451?: CVE-2025-51451 is a critical-severity vulnerability in Totolink Ex1200t, classified under Improper Authentication. CVSS score: 9.8/10. Published 2025-08-13.
How severe is CVE-2025-51451?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2025-51451 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.