What is CVE-2021-20986?

CVE-2021-20986 is a high-severity vulnerability in Hilscher Profinet Io Device, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2021-02-16.

How severe is CVE-2021-20986?

High severity. CVSS v3 base score is 7.5 out of 10.

Buffer overflow in Hilscher Profinet Io Device

CVE-2021-20986

A Denial of Service vulnerability was found in Hilscher PROFINET IO Device V3 in versions prior to V3.14.0.7. This may lead to unexpected loss of cyclic communication or interruption of acyclic communication.

Vulnerability class: Buffer Overflow

Published 2021-02-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.010 (62.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 63rd percentile — 62.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: +0.000

Affected products

Hilscher Profinet Io Device — versions V3
Hilscher Profinet Io Device
Hilscher Profinet Io Device Firmware
Pepper+fuchs Ohv — versions OHV-F230-B17
Pepper+fuchs Oit — versions OIT500-F113-B17-CB
Pepper+fuchs Pcv/pxv/pgv — versions PGV100-F200A-B17-V1D, PGV150I-F200A-B17-V1D, PGV100-F200-B17-V1D-7477, PXV100-F200-B17-V1D, PXV100-F200-B17-V1D-3636, PCV80-F200-B17-V1D, PCV100-F200-B17-V1D, PCV50-F200-B17-V1D, PCV100-F200-B17-V1D-6011-6997
Pepper+fuchs Pha — versions PHA300-F200-B17-V1D, PHA400-F200-B17-V1D, PHA300-F200A-B17-V1D, PHA300-F200-B17-T-V1D, PHA200-F200A-B17-V1D, PHA200-F200-B17-V1D, PHA400-F200A-B17-V1D, PHA300-F200A-B17-T-V1D, PHA600-F200A-B17-V1D, PHA500-F200-B17-V1D, PHA500-F200A-B17-V1D, PHA600-F200-B17-V1D, PHA150-F200A-B17-V1D, PHA200-F200A-B17-T-V1D, PHA150-F200-B17-V1D, PHA800-F200-B17-V1D, PHA400-F200A-B17-T-V1D, PHA500-F200A-B17-T-V1D, PHA700-F200-B17-V1D
Pepper+fuchs Pxv/pgv B28 Profisafe — versions PXV100A-F200-B28-V1D, PXV100A-F200-B28-V1D-6011, PGV100A-F200-B28-V1D, PGV100A-F200A-B28-V1D, PGV100AQ-F200A-B28-V1D, PGV100AQ-F200-B28-V1D, PXV100AQ-F200-B28-V1D, PXV100AQ-F200-B28-V1D-6011
Pepper+fuchs Wcs — versions WCS3B-LS610, WCS3B-LS610H, WCS3B-LS610D, WCS3B-LS610DH, WCS3B-LS610H-OM, WCS3B-LS610DH-OM, WCS3B-LS610D-OM, CS3B-LS610-OM
Pepperl-Fuchs Ohv-F230-B17

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

kb.hilscher.com/display/ISMS/2020-12-03+Denial+of+Service+vulnerability+in+PROF… (Vendor Advisory)
cert.vde.com/en-us/advisories/vde-2021-006 (Third Party Advisory)

Frequently asked questions

What is CVE-2021-20986?: CVE-2021-20986 is a high-severity vulnerability in Hilscher Profinet Io Device, classified under Out-of-bounds Write. CVSS score: 7.5/10. Published 2021-02-16.
How severe is CVE-2021-20986?: High severity. CVSS v3 base score is 7.5 out of 10.