Buffer overflow in Huawei Harmonyos

CVE-2026-34866

Out-of-bounds write vulnerability in the WEB module.Impact: Successful exploitation of this vulnerability will affect availability and confidentiality.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.1 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L.

EPSS exploit prediction

EPSS: 0.001 (1.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 1st percentile — 1.2% 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-2026-34866: held from 0.001 to 0.001.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-34866?
CVE-2026-34866 is a medium-severity vulnerability in Huawei Harmonyos, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 5.1/10. Published 2026-04-13.
How severe is CVE-2026-34866?
Medium severity. CVSS v3 base score is 5.1 out of 10.