What is CVE-2020-4988?

CVE-2020-4988 is a critical-severity vulnerability in IBM Loopback. CVSS score: 9.8/10. Published 2020-12-21.

How severe is CVE-2020-4988?

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

Vulnerability in IBM Loopback

CVE-2020-4988

Loopback 8.0.0 contains a vulnerability that could allow an attacker to manipulate or pollute Javascript values and cause a denial of service or possibly execute code. IBM X-Force ID: 192706.

Published 2020-12-21 · 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: 0.015 (73.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 73.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.015 · change: +0.001

Affected products

IBM Loopback — versions 8.0.0
Loopback — versions 8.0.0

References

exchange.xforce.ibmcloud.com/vulnerabilities/192706 (VDB Entry, vdb-entry, Vendor Advisory)

Frequently asked questions

What is CVE-2020-4988?: CVE-2020-4988 is a critical-severity vulnerability in IBM Loopback. CVSS score: 9.8/10. Published 2020-12-21.
How severe is CVE-2020-4988?: Critical severity. CVSS v3 base score is 9.8 out of 10.