How severe is CVE-2021-26859?

High severity. CVSS v3 base score is 7.7 out of 10.

Vulnerability in Microsoft Power Bi Report Server

CVE-2021-26859

Microsoft Power BI Information Disclosure Vulnerability

Published 2021-03-11 · last modified 2026-08-19.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.030 (87.0th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 87.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.030 · newest: 0.030 · change: 0.000

Affected products

Microsoft Power Bi Report Server — versions 15.0.1103.234, 15.0.1104.300
Microsoft Power Bi Report Server Version 15.0.1103.234 — versions 15.0.0.0
Microsoft Power Bi Report Server Version 15.0.1104.300 — versions 15.0.0.0

References

af854a3a-2127-422b-91ae-364da2661108 (Patch, Vendor Advisory)
msrc.microsoft.com/update-guide/vulnerability/CVE-2021-26859 (vendor-advisory, patch)

Frequently asked questions

What is CVE-2021-26859?: CVE-2021-26859 is a high-severity vulnerability in Microsoft Power Bi Report Server. CVSS score: 7.7/10. Published 2021-03-11.
How severe is CVE-2021-26859?: High severity. CVSS v3 base score is 7.7 out of 10.