What is CVE-2018-21200?

CVE-2018-21200 is a medium-severity vulnerability in NETGEAR R7800, classified under Out-of-bounds Write. CVSS score: 6.8/10. Published 2020-04-28.

How severe is CVE-2018-21200?

Medium severity. CVSS v3 base score is 6.8 out of 10.

Buffer overflow in NETGEAR R7800

CVE-2018-21200

Certain NETGEAR devices are affected by a stack-based buffer overflow by an authenticated user. This affects R7800 before 1.0.2.40 and R9000 before 1.0.3.6.

Vulnerability class: Buffer Overflow

Published 2020-04-28 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.006 (46.6th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 47th percentile — 46.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

kb.netgear.com/000055149/Security-Advisory-for-Post-Authentication-Stack-Overfl… (Vendor Advisory)

Frequently asked questions

What is CVE-2018-21200?: CVE-2018-21200 is a medium-severity vulnerability in NETGEAR R7800, classified under Out-of-bounds Write. CVSS score: 6.8/10. Published 2020-04-28.
How severe is CVE-2018-21200?: Medium severity. CVSS v3 base score is 6.8 out of 10.