What is CVE-2019-20791?

CVE-2019-20791 is a critical-severity vulnerability in Google Openthread, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2020-04-28.

How severe is CVE-2019-20791?

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

Buffer overflow in Google Openthread

CVE-2019-20791

OpenThread before 2019-12-13 has a stack-based buffer overflow in MeshCoP::Commissioner::GeneratePskc.

Vulnerability class: Buffer Overflow

Published 2020-04-28 · 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: 0.009 (58.7th percentile), scored 2026-10-25.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 59th percentile — 58.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Google Openthread

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

bugs.chromium.org/p/oss-fuzz/issues/detail (Exploit, Mailing List, Third Party Advisory)
github.com/openthread/openthread/commit/b8c3161281f8e15873f8decabd8eac461717aefe (Patch, Third Party Advisory)
github.com/openthread/openthread/commit/c3a3a0c424322009fec3ab735fb20ce8f6e19e70 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2019-20791?: CVE-2019-20791 is a critical-severity vulnerability in Google Openthread, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2020-04-28.
How severe is CVE-2019-20791?: Critical severity. CVSS v3 base score is 9.8 out of 10.