Buffer overflow in TP-Link Tapo C520ws

CVE-2026-34118

A heap-based buffer overflow vulnerability was identified in TP-Link Tapo C100/C101 v5, C210 v3.6 and C520WS v2.6 in the HTTP POST body parsing logic due to missing validation of remaining buffer capacity after dynamic allocation, due to insufficient boundary validation when handling externally supplied HTTP input.   An attacker on the same network segment could trigger heap memory corruption conditions by sending crafted payloads that cause write operations beyond allocated buffer boundaries.  Successful exploitation causes a Denial-of-Service (DoS) condition, causing the device’s process to crash or become unresponsive.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (42.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 43rd percentile — 42.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-34118: held from 0.004 to 0.005.

EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34118?
CVE-2026-34118 is a medium-severity vulnerability in TP-Link Tapo C520ws, classified under Heap-based Buffer Overflow. CVSS score: 6.5/10. Published 2026-04-02.
How severe is CVE-2026-34118?
Medium severity. CVSS v3 base score is 6.5 out of 10.