What is CVE-2025-51630?

CVE-2025-51630 is a critical-severity vulnerability in Totolink N350rt, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2025-07-17.

How severe is CVE-2025-51630?

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

Buffer overflow in Totolink N350rt

CVE-2025-51630

TOTOLINK N350RT V9.3.5u.6139_B20201216 was discovered to contain a buffer overflow via the ePort parameter in the function setIpPortFilterRules.

Vulnerability class: Buffer Overflow

Published 2025-07-17 · last modified 2026-06-17.

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: 0.005 (36.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 37th percentile — 36.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Totolink N350rt
Totolink N350rt Firmware — versions 9.3.5u.6139_b20201216

Weakness classification (CWE)

CWE-120 — Buffer Copy without Checking Size of Input (Classic Buffer Overflow)

References

github.com/luckysmallbird/Totolink-N350RT-Vulnerability/blob/main/1-ePort.md (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2025-51630?: CVE-2025-51630 is a critical-severity vulnerability in Totolink N350rt, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 9.8/10. Published 2025-07-17.
How severe is CVE-2025-51630?: Critical severity. CVSS v3 base score is 9.8 out of 10.