What is CVE-2020-26296?

CVE-2020-26296 is a high-severity vulnerability in Vega, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2020-12-30.

How severe is CVE-2020-26296?

High severity. CVSS v3 base score is 8.7 out of 10.

XSS in Vega

CVE-2020-26296

Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs. Vega in an npm package. In Vega before version 5.17.3 there is an XSS vulnerability in Vega expressions. Through a specially crafted Vega expression, an attacker could execute arbitrary javascript on a victim's machine. This is fixed in version 5.17.3

Vulnerability class: XSS (Cross-Site Scripting)

Published 2020-12-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.

EPSS exploit prediction

EPSS: 0.017 (76.5th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 76th percentile — 76.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.017 · newest: 0.017 · change: +0.000

Affected products

Vega — versions < 5.17.3
Vega Project

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/vega/vega/security/advisories/GHSA-r2qc-w64x-6j54 (Third Party Advisory)
github.com/vega/vega/issues/3018 (Third Party Advisory)
github.com/vega/vega/pull/3019 (Third Party Advisory)
github.com/vega/vega/releases/tag/v5.17.3 (Third Party Advisory, Release Notes)
www.npmjs.com/package/vega (Third Party Advisory)

Frequently asked questions

What is CVE-2020-26296?: CVE-2020-26296 is a high-severity vulnerability in Vega, classified under Cross-site Scripting. CVSS score: 8.7/10. Published 2020-12-30.
How severe is CVE-2020-26296?: High severity. CVSS v3 base score is 8.7 out of 10.