What is CVE-2019-11859?

CVE-2019-11859 is a medium-severity vulnerability in Sierrawireless Airlink Es440, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.0/10. Published 2020-08-21.

How severe is CVE-2019-11859?

Medium severity. CVSS v3 base score is 6.0 out of 10.

Buffer overflow in Sierrawireless Airlink Es440

CVE-2019-11859

A buffer overflow exists in the SMS handler API of ALEOS before 4.13.0, 4.9.5, 4.9.4 that may allow code execution as root.

Vulnerability class: Buffer Overflow

Published 2020-08-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:H/I:H/A:L.

EPSS exploit prediction

EPSS: 0.020 (79.8th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 80th percentile — 79.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.020 · newest: 0.020 · change: 0.000

Affected products

Weakness classification (CWE)

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

References

source.sierrawireless.com/resources/security-bulletins/sierra-wireless-technica… (Vendor Advisory)

Frequently asked questions

What is CVE-2019-11859?: CVE-2019-11859 is a medium-severity vulnerability in Sierrawireless Airlink Es440, classified under Buffer Copy without Checking Size of Input (Classic Buffer Overflow). CVSS score: 6.0/10. Published 2020-08-21.
How severe is CVE-2019-11859?: Medium severity. CVSS v3 base score is 6.0 out of 10.